econservationthe online magazine No. 18, February 2011
Cont
empo
rary
ArtW
allC
lock
byPa
ulaA
rt
edit
oria
l
The job market… where is it going?
The field of conservation‐restoration has been changing considerably in front of our eyes during the
last few years. Fuelled by the so called ‘crisis’, our profession has been no oasis for the social‐
economic changes that are taking place. Its strongest impact is on the job market, and can be seen
clearly in its deregulation and chaotic existence. The job market is the core of the problem, starting
with the free workforce for internships and ending with the low career prospects for senior
professionals. This system was already established long before the emergence of these difficult
times. However, the crisis has increased the problem to levels never seen before to such an extent
that cultural heritage is in peril.
Of course, the direct reason is the lack of money flow, which is felt deeply by everyone, from large
public institutions to small conservation businesses. A direct consequence of this is that
professionals, especially recent graduates in conservation, are seeking jobs in other areas, either
because after five long years of study they can’t find a position in their area of specialisation, or
simply because other jobs are better paid.
The problems occur when, after having graduated from a degree in conservation, the possibility of
finding a job is virtually inexistent so instead, graduates often seek a suitable internship, which will
hopefully open doors in the job market. This is more often than not an unpaid internship, as the
paid internships are difficult to encounter. It is possible to choose to work for a company but
international or renowned institutions are much better for the curriculum vitae. These are usually
run for educational purposes, and are non‐profit making institutions, thus it’s only natural that for
them, internships are seen as a type of volunteer work. However, in such places interns just replace
other interns, only few of them being actually integrated into the staff. So one moves on to another
internship or a ‘temporary’ job.
Experienced conservators are no better off. As I have noticed, having experience is not necessarily a
plus on the job market. More and more, older conservators in apparently permanent positions have
to be let go, and replaced by interns or (underpaid) early career professionals. This of course allows
institutions to meet their budgets but it also denotes a tremendous disrespect for the highly
experienced professional, not as an individual but as a whole. It also means that cultural heritage
itself is being cared for in a greater extent by less experienced hands. A direct consequence of this is
that these older professionals must return to the job market but for them this is much more difficult
to achieve as age becomes a factor versus experience in a society where youth is perpetually a
prized quality.
This system goes far beyond conservation and it’s very hard to break without a common strategy from
regulators, universities and employers. The true quality of life is nowadays becoming lower and lower
and we are loosing rights that had once been battled for. It is a serious problem with consequences I
cannot foresee but I know they will be a decisive factor for the future of the profession.
Sooner or later something has to give. Why should it be conservation?
Rui BordaloEditor‐in‐Chief
e‐conservation
NEWS & VIEWS 6
ARTICLES
CASE STUDY
32
#culturematters
By Daniel Cull
REVIEWS
Parchment and Leather
Research, conservation‐restoration, craft
Review by Tomasz Kozielec
Seven Years Dedicated to the Conservation of the Modern
Movement Heritage
The Conference Series: “Das architektonische Erbe – zum aktuellen
Umgang mit den Bauten der Moderne”
Review by Maria Bostenaru Dan
NEWS
Website: Google Art Project
Book release: The Orthodox Christian Sakkos
UPCOMING EVENTS
March ‐ April 2011
Infrared Reflectography Using 3D Laser Scanning
By Christian Dietz, Gianluca Catanzariti and Alfredo Jimeno Martínez
A Reflection on the Preventive Conservation of Archaeological Wood
and the Effects of Mass Tourism
The Case Study of the Vasa Warship
By Cristina Cabello‐Briones
The Use of Ground Penetrating Radar for the Assessment of the
Conservation State of an Historic Building
By Lucian Cristian Ratoiu
Virtual Aesthetic Presentation of Polychrome Sculptures
Preserving the artistic authenticity of polychrome carved wood
pieces in the conservation‐restoration process
By Daniela Cristina Pintilie
EVENTS
8
53
43
28
19
52
27
29
8
27
INDEX
e‐conservation 5
new
s&
view
s#CULTUREMATTERS
A pamphlet the Demos think‐tank
published a few years ago, entitled
‘It's a Material World’ [2], has been
a growing influence upon the con‐
servation community, and recently
IIC published an update from one
of the authors [3]. The stated aim
of these publications was to raise
awareness and champion “in wider
society and politics” [3, p. 242] the
values of heritage conservation.
I particularly appreciated the idea
that conservation has a unique role
within society in that “conservators
provide a paradigm not just for fix‐
ing things when they are broken, but
for a wider social ethos of care, where
we individually and collectively take
responsibility and action” [2, p. 16].
In thinking about this I remembered
a lecturer I had at University who
once said, and I paraphrase, ‘If you
really wanted to save heritage, you’d
go into politics’. At the time this
struck me as an interesting state‐
ment, and looking back it was per‐
haps bizarrely the moment that I
realized I wanted to study conser‐
vation. Sometime later a visiting
lecturer who was associated with
the EZLN [4] lectured to us about
the importance of cultural heritage
to the Maya of Chiapas, Mexico, and
for me the circle was squared. Just
as I realized art, culture, and politics
"Why should the lamp or the house be an art object, but not our life?"
(Michel Foucault, 1984) [1]
By Daniel Cull
are as much about everyday life as they are about
the contents of cases in museums, I also realized
that not all interactions between cultural heritage
and politics take place between white men in the
board rooms of quasi‐governmental heritage or‐
ganizations.
The 'Material World' writings were primarily aimed
at a western audience in response to the current
economic climate in which arts and cultural in‐
stitutions are increasingly being asked to justify
their existence in economic terms. The authors
developed the concept of ‘social capital’ as an
alternative to the economic approach, they con‐
sider conservation as a spectrum of activities from
the highly technical to those that anyone with a
bit of training could do, therefore they call for
an increase in volunteerism, with the logical as‐
sumption that this will lead to communities see‐
ing value in supporting heritage. As the Middle
East is realizing, and this pamphlet noted, “the
social glue that holds communities together is
changing. We are not talking to each other less;
we are talking to each other differently” [5, p. 8].
Many of these changes are coming as a result of
the logic of the emerging social media, the logic
of total access and community control. Although
the authors realize that through this emerging
media we can “help reconnect and facilitate the
formation of new geographic communities" [5,
p. 8], they appear to miss or underplay the poten‐
tial for alternative or hybrid forms of funding.
Although crucially they radically invert Maslovian
principles to state "preservation is not a sign of
decadence, but a sign of wisdom" [5, p. 6].
e‐conservation
The title of the ‘Material World’ pamphlet was in‐
tended as “a bold statement of fact, a reminder of
the role that objects, buildings, and ideas play in
anchoring society” [3, p. 243]. However, I read it
through the prism of the movement within conser‐
vation theory towards the value placed on safe‐
guarding the immaterial and metaphysical, and
recently reconsidered the collection of writings
in light of the events in Egypt in which, during the
popular uprising, risks of looting were noted at
cultural institutions across the country. Whilst
many cultural institutions in the West called for
state intervention to protect objects, the protest‐
ers on the streets had already taken matters into
their own hands and protected the museums, ar‐
chives and cultural sites [6]. In so doing we wit‐
nessed that when people have “an active relation‐
ship with the past” [3, p. 247] they’re not only
willing to volunteer to cut the grass around the
Cerne Giant but they’re willing to risk their lives
for their cultural heritage. Their actions were as
profound a statement on the value of conserva‐
tion to society as I imagine I will ever see. Their
actions suggest that it is not the artifacts them‐
selves that are important, but the relationship
that people have to them, and through them to
each other, that makes them important. As her‐
itage practitioners perhaps our most significant
role then is to help generate and facilitate peoples
'active relationships' with their cultural heritage.
For ultimately it’ll be the people who decide the
future of the past.
Bibliography
[1] M. Foucault, “On the Genealogy of Ethics: An
Overview of Work in Progress”, in The Foucault
Reader, Paul Rabinow (ed.), Pantheon Books,
New York, 1984, p. 236
[2] S. Jones and J. Holden, It's a Material World:
Caring For the Public Realm, Demos, London, 2008,
available at URL [pdf], accessed on February 20,
2011
VIEWS
e‐conservation 7
The NDP building burns next to the Egyptian Museum. Photo by darkroom productions, January 29, 2011. Some rights reserved.
VIEWS
8 e‐conservation
[3] S. Jones, "It’s a Material World", Studies in
Conservation 55(4), 2010, pp. 242‐249
[4] Ejército Zapatista de Liberación Nacional,
available at URL, accessed on February 20, 2011
[5] Anna Somers Cocks interview with Samuel
Jones, Dialogues for the New Century series, IIC
Tanks and soldiers guard the Egyptian Museum. Photo by Nebedaay, January 25, 2011. Some rights reserved.
DANIEL CULLConservatorThe Musical Instrument Museum
Daniel Cull is from the West Country of the British Isles. He trained at the Institute of Archaeology,
University College London, where he received a BSc in Archaeology, MA in Principles of conservation,
and an MSc in Conservation for Archaeology and Museums. He was later awarded an Andrew W. Mellon
Fellowship at the National Museum of the American Indian/Smithsonian Institution, Washington, DC.
He currently works as a conservator at the Musical Instrument Museum and as a collaborator with
e‐conservation magazine.
Website: http://dancull.wordpress.com
Contact: [email protected]
Annual General Meeting, 2010, Sackler Centre,
Victoria and Albert Museum, London, January
28, 2010, available at URL [pdf], accessed on
February 20, 2011
[6] Looting spreads in Egyptian cities, Al Jazeera
English, 29 Jan 2011, available at URL, accessed
on February 20, 2011
Review by Tomasz Kozielec
The international conference “Parchment and
Leather – research, conservation‐restoration,
craft” was organized by the Department of Paper
and Leather Conservation of the Nicolaus Coper‐
nicus University in Toruń, Poland, and took place
on October 21‐23, 2010. The conference was at‐
tended by representatives of institutions from
different countries who also presented lectures
on current conservation‐restoration issues and
modern research techniques. A concert on harp‐
sichord, “At Bach's home” by Ryszard Moroz, as
well as the exhibition “Conservation‐restoration of
gilt leather – students and their adviser” by Halina
Rosa were some of the highlights of this event.
The conference was divided into nine sessions
devoted to broad views of research problems and
questions regarding conservation of historic parch‐
ment and leather artefacts. After the registration,
the opening speech was given by Elżbieta Jabłoń‐
ska, Head of the Department of Paper and Leather
Conservation.
Justyna Król Weronika Liszewska and Zofia Żukow‐
ska, from the Faculty of Conservation‐Restoration
of Old Prints and Graphics, Academy of Fine Arts,
Warsaw Polytechnic (Poland), delivered the first
lecture entitled “Non–destructive analyses of il‐
luminated manuscript on parchment ’Testamentum
Vetus’ from the first half of the 14th century, from
the collection of the Higher Clerical Seminary in
Włocławek”. Besides visual examination of the
decayed areas of illuminations, Laser Induced
Breakdown Spectroscopy (LIBS) and Raman spec‐
troscopy were performed. The results of the ana‐
lysis were determinant for the better planning of
the conservation‐restoration treatments.
The second lecture was given by Agnès Le Gac, from
the Department of Conservation‐Restoration of
October 21‐23, 2010
Toruń, Poland
Organized by:The Department of Paper and Leather Conservation
of the Nicolaus Copernicus University
http://www.zkpis.umk.pl/
PARCHMENT AND LEATHER –RESEARCH, CONSERVATION‐RESTORATION, CRAFT
REVIEWS
e‐conservation 9
Opening speach by Elżbieta Jabłońska, Head of the Depart‐ment of Paper and Leather Conservation.
Exhibition of cordovans.
the New University of Lisbon (Portugal), who pre‐
sented “White leather glue: its reconstitution,
analysis and comparison with both parchment
and rabbit‐skin glues”. The researcher used SEM‐
EDX, originating visual and elemental mapping
images, to analyse white leather, parchment and
samples of glues. This research is important, among
other things, in the study of the rich polychrome
coatings applied on the 17th‐18th century religious
sculptures in Portugal. Closing the first session,
and after a coffee‐break, the participants had the
opportunity to attend the opening of the exhibi‐
tion “Conservation‐restoration of gilt leather –
students and their adviser”.
Afterwards, the lecture on “Biodeterioration of
historic parchment and leather – a summary of
studies in the Department of Paper and Leather
Conservation” given by Joanna Karbowska‐Ber‐
ent, from that same department at the Nicolaus
Copernicus University, opened the second session
and described research carried out on vegetable
and alum tanned leathers and parchments (mainly
from historical objects). Many processes and de‐
gradation stages of the materials caused by dif‐
ferent microorganisms were observed. As seen, one
of the most important factors in stopping biode‐
terioration is the presence of vegetable tannins
which protect the collagen fibbers against decay.
The presentation “Some early examples of sewing
tackets and thonged extensions” by Matthew Hat‐
ton, from the Glucksman Conservation Department
of the Trinity College Library in Dublin (Ireland),
emphasized eclectic problems of fragmented texts
in collections (which were brought together to
form single or multiple volumes) based on the
example of manuscript 1337 “Miscellanea Hiiber‐
nica”. Among the many interesting facts he de‐
scribed, the author presented interesting solutions
of restoration.
The afternoon session started with Marlena Viha‐
kara and Wiebke Findeisen, from the Centre for
10 e‐conservation
A general view of the conference hall.
REVIEWS
Preservation and Digitisation, The National Lib‐
rary of Finland, with their lecture “Conservation
and digitisation of medieval parchment fragments
in the National Library of Finland” in which they
presented the great and large collection of that
Library, and the making of the project “Save the
Book”. This project assumes the digitization, docu‐
mentation and basic conservation treatments.
The lecture on “Technology study and conservation
of thirteen traditional rural shoes of 19th century
from Florina region, northern Greece” was given
by Ekaterini Malea and Anastasia Tampaka, from
the Technological Educational Institute of Athens
(Greece), broadening the knowledge on techno‐
logy of leather shoes from 1900‐1935 from that
region. The authors presented the conservation‐
restoration treatments performed as well as the
subject of a footwear exhibition.
The next lecture, entitled “Parchment scrolls in
the collection of the Jewish Historical Institute –
project of the returning memory. Decoding for‐
bidden meanings” by Violetta Bachur, from the
Jewish Historical Institute in Warsaw (Poland),
introduced the conference participants to the
world of great Jewish art and craft. The different
types of parchments and methods of preparation,
Jewish scrolls, mezuzot, and many other sacred
e‐conservation 11
objects, as well as the Jewish law were presented
in detail. She also indicated the state of preser‐
vation of these objects.
The fourth session started with two lectures on
the history, techniques of making and restoring
cordovans (also called “gilt” or “Spanish leather”).
This session was opened by Ojcumiła Sieradzka‐
Malec, from the Royal Wawel Castle in Cracow (Po‐
land), with the presentation of “Wawel’s cordovans
– the issues’ outline”. The lecture focused on the
decoration history of the Royal Wawel Castle in
Cracow with the description of some technical
aspects.
The next presentation, “Conservation‐restora‐
tion of cordovans – problems and solutions” by
Halina Rosa from the Department of Paper and
Leather Conservation of the Nicolaus Copernicus
University, showed the long history and method
of preparation of cordovans from ancient times.
The oldest written source on gilt leather is the
description of Peder Manson from the 1515. The
main part of her speech was about the state of
preservation and conservation‐restoration prob‐
lems, such as the levelling deformations of cor‐
dovans and the cleaning of the painting layer.
She shared her wide and long experience on this
field with the participants.
REVIEWS
Presentation by Joanna Karbowska‐Berent, Department ofPaper and Leather Conservation, Nicolaus Copernicus Uni‐versity, Toruń, Poland.
Ojcumiła Sieradzka‐Malec from Cracow, Poland, speakingabout problems with gilt leather decorating the Royal WawelCastle.
Grażyna Macander‐Majkowska, also from the Acad‐
emy of Fine Art in Warsaw, approached a very in‐
teresting subject ‐ “Pastel portrait on parchment
– the unique work of art” ‐ certainly convincing
all participants that such great historical objects
are outstanding works of art (i. e. have a specific
technique). The work of artists who were using
the pastel technique reached its apogee in the
18th century. The author discussed two examples
of pastels from the second half of 18th century.
The parchment theme was continued by Katarzyna
Nowak, Anna Rychter and Aleksandra Szalla‐Klee‐
mann, from the Conservation Section of the De‐
partment of Preservation Jagiellonian Library
Collection in Cracow, with the presentation of
“Variety of use of parchment as bookbinding and
writing material in the collection of the Jagiello‐
nian Library”. The authors indicated the use of
this material for bookbinding purposes such as
raised bands, cloth joints or pastedowns, flyleafs,
covers, and for the making of sheets of manuscripts
and prints. They showed that parchment has a
very good durability, permanence, and state of
preservation if stored in proper and stable condi‐
tions of temperature and relative humidity. The
authors also posed questions concerning the dis‐
covery of codex fragments during conservation‐
restoration treatments.
The morning of the second day started with a series
of announcements and short presentations. One
that must be highlighted was dedicated to the
Museum of Literature and Printing in Grębocin, a
museum of writing, printing, paper‐making, and
bookbinding history and technology on the sub‐
urbs of Toruń. The great “pearl” of this region was
presented by its founder and head, Dariusz Subocz
with “The machines and bookbinder devices in the
collection of Literature and Printing Museum in
Grębocin”. Examples of papermaking moulds, book‐
binding and writing tools, composition of old inks,
organized in past museum workshops, giving know‐
ledge on the processing of animal skins into leath‐
er and parchment, and on how to produce paper
by hand, as well as how to print, sew and cover
books, and many others subjects were presented.
“Parchment Torah from Lubaczów – conservation
problems and solutions”, again by Katarzyna Nowak,
was the next interesting lecture. The analysis of
the technique, the state of preservation, causes
of destruction and conservation treatments of
this intensively deteriorated object were presen‐
ted. The use of neodymium magnets for restora‐
tion purposes was one of many other interesting
solutions shown. The theme of museum collection
initiated by Dariusz Subocz was continued by Mo‐
nika Zakroczymska's lecture “The short charac‐
teristics of the collection of Museum in Gdynia”,
from the Museum of City Gdynia (Poland). The
collection of photographs, documents, maps and
plans, posters and diverse material culture items
(such as furniture, home and gardening devices,
clothes, flags, dishes, and decorations) were
presented.
Another enthralling museum collection was pre‐
sented by Ewa Martin‐Sobecka, entitled “Collec‐
tion of leather objects in Ethnographic Museum
in Toruń”. There are almost 60.000 different ob‐
jects in their collection! Haberdashery, furniture
upholstery, small bellows used in beekeeping,
leather hand‐bags and bags, suitcases, spectacle‐
case, holders for knives, razors, cigarette cases,
wallets, purses, briefcases and watch straps and
many other leather objects were showed in the
presentation.
The fifth session was opened with “Conservation‐
Restoration of Nubian Leather Finds from the 11th
Century” by Myriam Krutzsch, from the Egyptian
Museum in Berlin (Germany), Claudia Näser, from
the Humboldt University in Berlin, and Patricia
12 e‐conservation
REVIEWS
Engel, from the European Research Centre for Book
and Paper Conservation‐Restoration in Horn (Aus‐
tria). Specifications and conservation treatments
of 100 fragments of inscribed parchment, numer‐
ous remains of leather bindings with a multitude
of decorative elements and several texts on folded
leather were shown. The presented materials were
especially important for leather conservators be‐
cause little is known about bookbinding in 11th
century Nubia. The authors focused also on the
“Step leather project” and the “Environmental
Leather Projects”.
“Protecting works over the Coptic parchment manu‐
script (the 9th and 10th century) and the specificity
of its destruction” by Anna Thommée, from the
Department of Art, Collection, Books and Docu‐
ments Conservation in Toruń, was an interesting
example of full description of conservation treat‐
ments carried out from “rescue” treatments to the
stage of making of protective wrappers. Three
manuscripts discovered by Polish archaeologists
were in very poor condition. Since 2006, the books
have been preserved in the National Museum Work‐
shop in Alexandria, in a common project of the
Mediterranean Archaeological Centre of Warsaw
University and Polish Workshops of Heritage
Conservation S.A.
Examples of beautiful parchment objects from
the collection of the Museum of Westphalia and
Lippe were presented by Ryszard Moroz, from the
Westphalian State Museum of Art and Cultural
History (LWL) in Münster (Germany) in his lec‐
ture “Open‐work parchment”. The unique tech‐
nique of such outstanding objects (ornamented
parchment by cutting out a variety of patterns
with great precision!) and their conservation
problems were emphasized.
The sixth session started with Sara Mazzarino's
lecture, from the British Library in London (UK),
on the “Humidification and tensioning of parch‐
ment manuscripts ‐ limitations and possibilities of
different method of parchment tensioning during
conservation treatments”. An important question
was raised: “Is it always appropriate to humidify
and tension degraded parchment documents?”.
In the lecture “Problems and questions connected
with the conservation of 15th‐century parchment
codex “Breviarium Vladislaviense”, by Weronika
Liszewska and Jacek Tomaszewski, from the Aca‐
demy of Fine Arts in Warsaw, the authors discussed
its state of preservation, historical, ethical and
aesthetical problems. A modern technique of filling
losses in parchment sheets by using of parchment‐
cellulose pulp mixture was presented along with
the description of the conservation treatments.
However, not only issues concerning the conser‐
vation‐restoration treatments were discussed dur‐
ing the conference. The fact that the documenta‐
tion is a very important “tool” for conservators
convinced Penelope Banou, Ourania Kanakari
and Angeliki Stassinou from the General State
Archives of Greece, to present “Documentation
as a tool to conservation of parchment collections
belonging to the General State Archives, Greece”.
They underlined that “the study of palaeography,
diplomatic elements (typology), technology of
"Conservation‐Restoration of Nubian Leather Finds from the 11th
Century” by Myriam Krutzsch, Claudia Näser and Patricia Engel.
e‐conservation 13
REVIEWS
materials and techniques, etc., were essential to
resolve conservation and preservation issues”,
and showed many interesting examples of solu‐
tions of conservation‐restoration problems.
“Conservation of a Trousseau Chest Coming from
Balkans to Turkey”, by Nil Baydar from Ankara Uni‐
versity (Turkey), was not only a full description of
construction technology but also of the conser‐
vation treatments carried out on this 18th century
object. Achieving a beautiful result was possible
due to a hard and long work (2 years) on seriously
decayed materials ‐ leather, corroded metals and
other.
Izabela Zając, from the Academy of Fine Arts in
Warsaw, started the seventh session with the
presentation of “Leather bindings – traps and
surprises” on which she demonstrated an example
of a valuable book cover which looked like leather
but was really parchment dyed brown. Another
issue discussed was the impossibility of determi‐
nation of fat content (in percentage) of ancient
leather for re‐greasing conservation treatment.
Sometimes some of the treatments which can be
carried out on ancient leather require complex
solutions. Examples are the recovery of the ori‐
ginal size of leather covers as well as the elimina‐
tion of deformations on the book spine.
Malaurie Auliac and Aline Leclercq, from Condé’s
School in Paris (France), raised a discussion about
the conservation of leather bindings with Japa‐
nese tissue”. The authors showed interesting solu‐
tions of the use of Japanese tissue, and results of
questionnaires conducted among conservators.
“The Missal from Kraśnik” (1400) – the chosen
conservation issues” by Jolanta Żuk Orysiak and
Ryszard Orysiak, from Lublin Museum in Lublin
(Poland), was a presentation about the conser‐
vation‐restoration of one of the most precious
“pearls” among the Polish collection of illumi‐
nated medieval manuscripts.
A very important question ‐ “should conservators
remove all visible dirt and anaesthetic remains
from the surface of materials during conserva‐
tion work?” ‐ gained special significance after
the lecture by Aleksandra Szalla–Kleemann, from
the Jagiellonian Library Collection in Cracow,
Anna Żukowska–Zielińska, from the Jagiellonian
University Archive in Cracow, and Joanna Sobczyk,
from the Laboratory of analysis and non‐destruc‐
tive investigations of heritage objects, National
Museum in Cracow, entitled “Banderia Prutenorum
– conservation search query. The authors used
digital imaging to recreate missing illumination
of the manuscript“. The “Banderia Prutenorum”
is a 15th century parchment codex with images
of 56 Teutonic and Prussian flags (some of them
were conquered during the Tannenberg Battle in
July 1410), from the collection of the Jagiellonian
Library. It is a good example of a successful re‐
construction of missed (cut off) parchment sheet
with illumination depicting the “Madonna with
Child”. Reconstruction was possible by digital
analyses of remains of the painting layer (hardly
visible smudges), on the page with the reflection
of Madonna on one side (back side of next illumi‐
nated parchment sheet). The digital analyses al‐
lowed the reconstruction of the outlines of the
“Madonna and Child”. In the end of the lecture, the
authors asked “what would have happened with the
Madonna reflection, if the pages of the manuscript
had been just – as it usually happens – cleaned?”.
After the coffee break and initiating a new session,
the lecture “The conservation and reconstruction
of the leather items which were found during the
archaeological research in Gdańsk” was presented
by Beata Ceynowa, from the Archaeological Mu‐
seum in Gdańsk (Poland). Although the examples
of leather objects from archaeological excavations
14 e‐conservation
REVIEWS
Małgorzata Grupa from the Archaeology Institute, NicolausCopernicus University, Toruń, Poland, speaking about methodsof conservation‐restoration of archaeological leather.
The presentation of conservation of archaeological leatherfrom Gdańsk Historic State Museum by Bartosz Iwaszkiewiczand Halina Rosa.
had a perfect state of preservation (due to the
high humidity with simultaneous absence of air,
among others!) many problems may arise during
their conservation treatments. These problems
are caused by: the separation of particular elements
of single products from bulk of others; financial
aspects – glycerine method of conservation is used
in most cases because it is often the simplest and
the cheapest treatment; reconstruction ‐ as little
intervention as possible.
The previous conservation issue was further de‐
veloped by another archaeologist, Anna Drążkow‐
ska from the Archaeology Institute of Nicolaus Co‐
pernicus University, in “Problems of conservation
and reconstruction of historical shoes” from dif‐
ferent historical periods and found during differ‐
ent excavations and in various environments. It
was emphasized that treatments such as disinfec‐
tion, cleaning and impregnation have a signific‐
ant influence on further reconstruction works. In
turn, Małgorzata Grupa, also from the same In‐
stitute, presented the methods of conservation of
the archaeological leather used in the Archaeolo‐
gical Institute of Nicolaus Copernicus University.
Conservation treatments in the Institute are con‐
ducted since 1983. Recently researchers focused
on the method of leather conservation at low tem‐
peratures by means of a vacuum chamber.
Bartosz Iwaszkiewicz and Halina Rosa, from the
Department of Paper and Leather Conservation
in Toruń, showed in their lecture “Conservation
of archaeological leather from the Historical Mu‐
seum of the City Gdańsk” a variety of archaeolo‐
gical elements that were found and analyses per‐
formed to those objects. They also presented stand‐
ard conservation treatments which are carried out
in the Department. Removal of black iron‐tannin
complexes through ultrasounds bathing in water
solution of EDTA with addition of the Vulpex soap,
re‐tanning with water‐acetone solutions of sumac,
and re‐greasing (van Soest mixture) are only some
examples of treatments they discussed.
On the last day, the eighth session was started by
Ryszard Moroz, from the Westphalian State Mu‐
seum of Art and Cultural History (LWL) in Münster
(Germany), in his lecture “The document case of
Baron von Stein and the gothic chest – the con‐
servation problems with accumulations on the
leather grain” presented an interesting technique
of two famous leather objects of Baron document
case, the outstanding German politician who lived
at the turn of the 18th and 19th centuries, and the
chest which is a museum rarity. The state of pre‐
servation of the objects was poor, one of the em‐
phasised issues being the accumulations on the
leather grain which were visible at naked eye.
e‐conservation 15
REVIEWS
“Conservation of the saddle in the western type
from the collection of the Horsemanship and Hunt‐
ing Museum in Warsaw ‐ the diversity of materials
and resulting conservation problems” by Dorota
Jutrzenka‐Supryn, from the Department of Paper
and Leather Conservation in Toruń, was a review
on techniques of ancient saddles. The author in‐
dicated that the objects forming the big group in
study are not original, but copies pretending to be
historical (especially from the 17th‐18th century).
Her lecture focused on the conservation treatment
of the saddle from the Warsaw Museum.
Finally, the last session was started with a lecture
by Elżbieta Górska‐Wiklo, from the Archive Uni‐
versity of Glasgow (Scotland), who described the
Archive collection which spans from 1304 to the
present. The author focused on the “Blackhouse
Charters”, the collection of parchment documents
dated between 13th and 18th centuries, which were
repacked and prepared for digitisation. It was also
mentioned the student's support within this pro‐
gramme, helping to developed their knowledge on
preventive conservation, methods of securing the
documents as well as on their storage.
Ethical issues in conservation‐restoration were
raised by Małgorzata Pronobis–Gajdzis and Wioleta
Ługowska, from the Department of Paper and
Leather Conservation in Toruń, in their presenta‐
tion “The parchment and the leather in the his‐
toric codices – the ethical issues”. The lecture sup‐
ported by the idea of Ksawery Piwocki's (“that not
only the work of art is important but the acting
of the artists also influences the value of the ob‐
ject”) was concerned on controversial examples
of removing original parts of codices. The authors
concluded that “the restorer must be aware that
there should not be any violations in the historic
quality of the object even if there are some efforts
to improve the aesthetics of the historic item”.
Elżbieta Jabłońska, Małgorzata Pronobis‐Gajdzis
and Jolanta Czuczko, also from the Department of
Paper and Leather Conservation in Toruń, raised
another important issue with their lecture “Copy‐
ing of precious documents and archival books as
good practice in protection during the exposition
and access”. Because of the unique character of
rare, extremely valuable historical objects, there
are cases when exhibiting the originals is impos‐
sible. For this reason, copies of original objects are
made. Examples of copies of rare historical objects
and copies made by students of the Department of
Paper and Leather Conservation were presented.
The large variety of these lectures testifies to the
fact that problems of research, preservation and
Saddle from the collection of the Horsemanship and HuntingMuseum in Warsaw, subject of the presentation by DorotaJutrzenka‐Supryn.
16 e‐conservation
REVIEWS
Presentation „The parchment and the leather in their historiccodices – the ethical issues” by Małgorzata Pronobis‐Gajdzisand Wioletta Ługowska.
methods of conservation‐restoration of parchment
and leather are a significant concern among con‐
servators. There is a wide variety of objects made
of leather and parchment in the world collections
and many of them surprise by their beauty or un‐
usual technique. The significant sensitivity of these
materials to physical, chemical and mechanical
factors motivate conservators to elaborate new
and safe methods for their conservation, and to
ensure stable storage conditions. Although the
conference has presented many interesting case
studies, describing different treatment methods
and analysis techniques, there are still many prob‐
lems that await solution. Another conference, this
time dedicated to the conservation‐restoration
of historic objects, is being planned for the near
future.
Credits: Photos in this review are by the conference
organizers.
FREE
CONSERVATION
RESOURCES
Art Conservation Research
conservationresearch.blogspot.com
TOMASZ KOZIELECConservator
Contact: [email protected]
Tomasz Kozielec is a paper and leather conservator. He
graduated in conservation from the Department of
Paper and Leather Conservation of the Nicolaus Co‐
pernicus University where he now lectures. His re‐
search interests are the history and technology of
cellulosic and proteinaceous materials, modern ana‐
lytical techniques of historical objects, and the ap‐
plication of new materials and methods for conserva‐
tion‐restoration purposes, such as the use of bacterial
cellulose and neodymium magnets, or the mass strength‐
ening of brittle 19th century papers.
REVIEWS
e‐conservation 17
Do you need an online presence?Do you feel it’s time to update to 'digital conservation'?
Do you have a website that looks like built in the last century?
www.Yconservation.comVisit our website
Yconservation is a collaborative project designed especially for individualsand small businesses in the cultural heritage field. We create online solutionsthat provide you with what you need, combining design, functionality andease of use. We offer HIGH QUALITY and LOW COST SOLUTIONS for yourbusiness or project.
GRAPHIC AND WEB DESIGN SERVICES FOR CONSERVATION
19e‐conservation
REVIEWS
Between 2004 and 2010, a series of one‐day con‐
ferences, always on Fridays, took place at the Uni‐
versity of Karlsruhe, Germany, in cooperation with
DOCOMOMO and supported by Beton Marketing
Süd, as research initiative of the university. The
topic of the conference was how to preserve and
use cultural heritage buildings of the Modern
Movement which define the face of today in many
European cities. Organiser was architect Alex Dill,
academic counsellor from the Institut für Baugestal‐
tung, Baukonstruktion und Entwerfen 2 (Institute
for Building Configuration, Building Construction
and Projects 2) (2004‐2007), the then head of the
chair of Architecture and Furniture from the Insti‐
tute Projects, Arts and Theory (2007‐2011). Each
conference was accompanied by an exhibition fo‐
cused on heritage of Modernity in the respective
geographic zones, the vernissage of which took
place in the evening. Starting with 2006 when the
German DOCOMOMO committee was redefined, the
days after the conference were reserved for the
meeting of the committee’s German chapter. The
conferences were recognised by the chamber of
architects as continued learning events for pro‐
fessionals, although they were also open to the
general public. The first three conferences focused
on the differences in the approach in Western and
Eastern Europe, having in focus a country from
each. The following conferences focused on one
country each. We attended all conferences, except
for the opening and closing ones.
Russia and Germany
The first conference took place in January 2004
and it focused on the challenges for architecture
SEVEN YEARS DEDICATED TO THE CONSERVATIONOF THE MODERN MOVEMENT HERITAGE
Karlsruhe, Germany, 2004‐2010 | Organised by Dipl. Ing. Alex Dill and DOCOMOMO Germany
Review by Maria Bostenaru Dan
Visit our website
The Conference Series:“Das architektonische Erbe – zum aktuellen Umgang mit den Bauten der Moderne”Architectural Heritage – on the Contemporary Approach to the Buildings of Modernity
Between 2004 and 2010 a series of seven conferences took place in Karlsruhe, Germany, on the conser‐
vation of architectural heritage throughout Europe. Aimed primarily at practicing architects, they were
organised by Dipl. Ing. Alex Dill, from the Faculty of Architecture, University of Karlsruhe, together with
DOCOMOMO (International Committee for DOcumentation and COnservation of buildings, sites and
neighbourhoods of the MOdern MOvement) and Beton Marketing Süd. It was also the framework in which
the German chapter of DOCOMOMO was re‐launched in 2006 and a declaration adopted. The countries in
focus were Germany, Russia, the Netherlands, Italy, Czech Republic, France, Sweden/Scandinavia and Great
Britain. The opening and closing conferences focused on Russia, for which lessons should be learned from
the functioning practice in conservation in Western and Central Europe. Outreach activities were accom‐
panying exhibitions, books releases, meetings of the DOCOMOMO chapter, and related conferences. In 2011
the series will be discontinued, being replaced by a conference on architecture theory: “Authenticity”.
of Modernity in Russia and Germany in a compar‐
ative approach. The approach was, as the confer‐
ence proved, fundamentally different – the pre‐
servation practices from the West did not reach
Russia and the buildings of the Russian construc‐
tivists, which are of fundamental importance for
the history of architecture, were first documented
and preserved in form of study models. It was also
an occasion to compare the different terms of
Avant‐garde, Modernism and Modernity. At the
time the buildings were erected, there were more
common features in the new practice than today
in conservation. Of use for the conference was the
cooperation between the University of Karlsruhe
and Russian specialists, some of which were visit‐
ing scientists in Karslruhe for several years, such
as Dr. Sergej Fedorov, also co‐organiser of the
conference. The conference was advertised on
the German internet portal of construction news
BauNetz. It was accompanied by an exhibition on
architecture models of the Russian Avant‐garde,
a cooperation project of the students from Karls‐
ruhe and of the University of Stuttgart. The con‐
ference took place on the last day of the exhibi‐
20 e‐conservation
REVIEWS
tion. Among the subjects approached were Russi‐
an Constructivist buildings from St. Petersburg and
Moscow, the house Schminke in Löbau [1] (figure
1) and the preservation and maintenance of Béton
brut (Sichtbeton). Later on, Rüdiger Kramm pub‐
lished a book on this topic [2], as accompanying
publication of the conference series.
The Netherlands and Russia
The second conference took place in October 2004
on the subject of the architecture from the Nether‐
lands, with some contributions about Russia and
Germany (Rettung vor dem Zerfall. Tagung an der
Fakultät für Architektur zur Erhaltung moderner
Bauten). Continuing the intentions of the first con‐
ference to facilitate the exchange and encourage
the preservation of the buildings of the Modern
Movement all over Europe, a delegation of the Mos‐
cow Institute of Architecture took part in the con‐
ference. The chair of the working group on Tech‐
nology of DOCOMOMO, Wessel de Jonge, presented
the restoration of the Sanatorium Zonnestraal in
Hilversum (the Netherlands; figure 2). From the
interesting problematic regarding the restoration
of the sanatorium, we can mention the replace‐
ment of the windows that had to be made out of
a special glass in order to reflect similarly, so the
Figure 1 (left). House Schminke, Löbau (Germany), architectHans Scharoun (1932‐33). Photo by Wojtek Gurak, Somerights reserved.Figure 2 (below). Sanatorium Zonnestraal, Hilversum (theNetherlands), architects Jan Duiker, Bernard Bijvoet andJan Gerko Wiebenga (1928). Photo by Pimvantend, Somerights reserved.
REVIEWS
21e‐conservation
sand to produce them sufficiently transparent
even in double glazing was imported from the
Baltic states. There was also a presentation of
the dean of the faculty Prof. Matthias Pfeifer on
structural restoration of buildings in Germany.
The corresponding exhibition displayed the work
of Konrad Wachsmann, a German architect who
immigrated to the US and was a pioneer of the
prefabricated construction. The University of
Karlsruhe has a database on German architects
who were active outside Germany (Architekten
im Exil 1933‐1945).
Italy (and Czech Republic)
The third conference took place in January 2006
and it focused on Italy, with Eastern/Central Europe
presentations about the Czech Republic. It was the
year when DOCOMOMO Germany was newly defined,
occasion to have the vice‐chair of DOCOMOMO in‐
ternational, Prof. Maristella Casciato, among the
speakers. Maristella Casciato gave an overview
talk on the research and practice of restoration
in Italy. It was followed by two case studies:
‐ the case of “Lingotto”, a hierarchical model, by
Christiana Chiorino from the Polytechnic University
of Turin. The author conducted research on the
preservation of Pier Luigi Nervi buildings in the
context of the XX Olympic Winter Games held in
Turin in 2006, focusing on the approach of rein‐
forced concrete and defining some criteria on
which buildings should be preserved for their
structural characteristics [3, 4];
‐ the case of “Ivrea”, a dynamic model, by Enrico
Giacopelli. Recent efforts of the presenter, together
with Patrizia Bonifazio, are taking place to include
the city of Ivrea on the UNESCO World Heritage List
[5‐7]. For this purpose, International Summer
Schools focused on the architecture and urbanism
are being organised. An open sky museum of mod‐
ern architecture (Museo a cielo aperto dell'Archi‐
tettura Moderna di Ivrea) exists in Ivrea since 2001
to promote cultural tourism for the valuation of
this heritage.
After the lunch break, two case studies from the
Czech Republic were presented: the Villa Müller in
Prague, by Petr Urlich from the Czech Technical
University, about research and practice of the
restoration; and Villa Tugendhat in Brno (figure
3, on which two presentations were given. The
first was by Iveta Cerná about the history of the
building and the other by Prof. Ivo Hammer from
the University of Applied Sciences and Arts (HAWK)
at Hildesheim / Vienna, whose research is dedic‐
ated to the “materiality” of surfaces built of ma‐
terials of the Modern Movement, such as steel and
glass.
In October 2005, before the conference, a team
of photographers from the Institut für Baugestal‐
tung, Baukonstruktion und Entwerfen 2 visited the
Villa Tugendhat, and an exhibition accompanied
the conference. Later, a photo documentation of
the Villa was published [8]. Three years later, in
June 2008, a further DOCOMOMO conference and
a chapter members meeting were organised exactly
at the Villa Tugendhat (minutes are available on‐
line), accompanied by the Declaration of Brno.
Figure 3. Villa Tugendhat, Brno (Czech Republic), architectLudwig Mies van der Rohe (1928‐39). Photo by Mr. Hyde, 2006.
REVIEWS
22 e‐conservation
France
The fourth conference took place in January 2007
and focused on the French architecture. It was
organised in cooperation with the Centre Culturel
Français at Karlsruhe, Germany. The overview talk
was given by Christiane Schmuckle‐Mollard, Chief‐
Architect at Historic Monuments, Paris. After a
discussion about Le Corbusier buildings listed as
UNESCO World Heritage by Michel Richard from
the Le Corbusier Foundation in Paris, case study
presentations followed. The Maison La Roche
(figure 4), where the foundation Le Corbusier is
situated, was renovated afterwards, in 2009, as
we had the occasion to learn during our visit. More
case studies were presented after the lunch break,
such as La Maison de Verre, Paris (1932, architect
Pierre Chareau), by Bertrand Bauchet. Chareau
was an architect whose interiors are characterized
by flexible partitions between the rooms ‐ sliding
walls and similar. Maison de Verre (The Glass House,
figure 5) is called this way due to its facade made
entirely of glass tiles [9]; Other case studies were
La Villa Cavroix in Croix (1932, architect Robert
Mallet‐Stevens), by Prof. Richard Klein, Lille; La
Villa E‐1027 in Roquebrune (1929, architects Eileen
Gray and Jean Badovici), by Prof. Rainer Franke,
Karlsruhe; Cité de La Muette – a vertical garden
city (1934, architect Marcel Lods), by Prof. Pieter
Uyttenhove from Ghent, Belgium, Le Havre and
Auguste Perret, by Prof. Joseph Abram, Nancy,
Paris.
There were also talks on Germany, such as the in‐
troductory one by Rüdiger Kramm on the approach
of the Modern Movement architecture today, de‐
tailing the diminishing acceptance for buildings
of the 1960s and the return to traditional housing
such as Fachwerk.
The conference was accompanied by an exhibition
about the city of ROYAN, a “ville nouvelle” of the
reconstruction 1947‐1959, photographs by Dirk
Altenkirch, Karlsruhe, a city built entirely after the
Second World War. This was the only conference
after which a publication was issued, containing
papers of the presentations in the original lan‐
guage, respectively German, English or French
[10]. In the meeting of the German chapter of
DOCOMOMO a “Declaration of Karlsruhe” was re‐
leased and can be consulted online.
Sweden (and Scandinavia)
The fifth conference took place in January 2008,
and it was focused on Sweden. This was also ad‐
vertised in BauNetz. The introductory speech
about the situation in Scandinavia was given by
Ola Wedebrunn, co‐chair of the DOCOMOMO Inter‐
Figure 4. Maison La Roche, Paris, France, architect Le Corbusier(1923). Photo by M. Bostenaru, 2010.
Figure 5. Maison de Verre, Paris (France), architect PierreChareau (1928‐31). Photo by Subrealistsandu, 2009, Somerights reserved.
REVIEWS
e‐conservation 23
national Technology working group from Copen‐
hagen. A second introductory talk was about the
20th century heritage in Sweden. These were fol‐
lowed by case studies such as The Upper School
for Girls, by Torbjörn Almqvist, from Stockholm,
The Civic Hall from Eslöv, by Mats Edström, who
also wrote a book on this subject [11], Siedlung
Vällingby, by Sven Lorentzi from Stockholm, and
The Town Hall in Göteborg, by Claes Caldenby,
among other not so extensively presented case
studies.
The accompanying exhibition was entitled “Bel‐
levue ‐ MOMONECO” focusing on the Bellevue, a
seaside resort in Denmark, and documented in
the frame of the European project MOMONECO,
“MOdern MOvement NEighbourhood Cooperation,
modernist dreams ‐ 4 case studies” funded through
the CULTURA 2000 European scheme. In the pro‐
ject there were 4 sites involved: Sunila in Finland,
Bellevue‐Bellavista in Denmark, Bat'ovany‐Par‐
tizánske in Slovakia and Ivrea in Italy. Except for
Bellevue, the other three were industrial sites.
The Bellevue resort was designed by the archi‐
tect Arne Jacobsen in the 1930s.
Great Britain
The sixth conference took place in January 2009
and it focused on Great Britain. Immediately after
the introduction, the president of DOCOMOMO
Great Britain and the editor of the extracts from
DOCOMOMO registries [12], Dennis Sharp, spoke
about the Modern Movement in Great Britain.
Overviews were presented by Keyvan Lankarani,
from Avanti Architects, London, Igea Troiani from
the University of Oxford and Alan Powers from
the University of Greenwich. These alternated
with presentations of case study as follows: the
architecture of Ernő Goldfinger, an Hungarian
immigrant less known outside Great Britain and
whose centenary took place recently, by James
Dunnet, from JD Architects, London; the restor‐
ation project of the De La Warr Pavilion (arch. Erich
Mendelsohn and Serge Chermayeff, figure 6), by
John McAslan from JMA Architects, London, a
project which was also the subject of a book [13];
and the Flat Roof House, 1934 (arch. C. Lucas),
by Yasmin Shariff from DS Architects, Hertford.
The last case study presented was about the Zeche
Zollverein Coal Mine Industrial Complex in Ger‐
many, listed as UNESCO World Heritage and an
example to be followed in the conversion of in‐
dustrial architecture through the IBA Emscher
Park project in Ruhr (European Capital of Culture
in 2010).
From the many presentations, one of the most
interesting was a peripheral Modern small scale
building that was a victim of speculation and was
demolished in order to use the property for a
higher building, which unfortunately could not
be avoided. However, the property was classified
as “green belt”, of obviously lower value than the
Modernist building. We could learn lessons from
this for other countries, such as Romania, where
recently, at the end of 2009, a low‐rise building
by interwar architect Henrietta Delavrancea Gibory
was demolished for similar reasons.
Figure 6. De la Warr Pavilion, Bexhill on Sea (UK), architectsEric Mendelsohn and Serge Chermayeff (1935). Photo byMarta Gutowska, 2006, Some rights reserved.
24
REVIEWS
e‐conservation
Another interesting talk was the presentation of
the Twentieth Century Society (C20 Society),
which seems to take over in Great Britain many
of DOCOMOMO's attributes.
The conference was followed by the vernissage
of two exhibitions, one in the well established
tradition regarding the architectural potential
of modern architecture by DOCOMOMO Great Bri‐
tain called “British Case Studies” (figure 7) and
the other regarding the prize of the Wüstenrot
Stiftung foundation from Germany concerning
projects in context (figure 8).
Russia (and Germany)
The seventh and last conference took place in
January 2010 and, like the first one from the
series, was focused on Russia and Germany. The
overview talk was given by Natalia Dushkina about
the Modern Movement Heritage in Russia. The
presented case studies from Russia were the Stu‐
dents Commune House (Arch. Nicolaev), project
and realization, by Vsevolod Kulish, Moscow, and
the Haus Narkomfin (Arch. Ginzburg), a project
by Alexey Ginzburg, Moscow.
In between the presentations on the two coun‐
tries there was an interesting overview on the
situation in Ukraine by Alexander Bouryak, from
Kharkiv (Ukraine).
The case studies presented from Germany were:
the Umspannwerk Berlin‐Scharnhorst, by Paul Kahl‐
feld, Berlin; the ADBG Schule Bernau (Arch. H.
Meyer), by Franz Jaschke, Berlin; and the Fagus
Werk (Arch. W. Gropius and A. Meyer), by Ulrich
Pagels, from Hannover.
The results of student studies were also presented,
such as the Avant‐Garde Heritage workshop in
St. Petersburg by Diana Zitzmann, and Alex Dill,
as well as the report from the excursion Magni‐
togorsk ‐ Ernst Mays buildings today by Thomas
Flierl, Berlin.
The exhibition was called “Avant‐Garde ‐ Defama‐
tion – World Cultural Heritage” and showed a con‐
trast between the approaches in the East and the
West, Russia and Germany.
Conclusions
In 2011, instead of the eighth conference from the
series, the organizers were planning, together with
the annual meeting of the DOCOMOMO chapter
Figure 7. Image of the exhibition hall in the main building ofthe architecture faculty, exhibition about “British Case Studies”,Photo by M. Bostenaru, 2009.
Figure 8. Image of the exhibition hall in the building “Kollegium‐gebäude am Ehrenhof”, exhibition “Gestaltungspreis derWüstenrot Stiftung”. Photo by M. Bostenaru, 2009.
25
REVIEWS
e‐conservation
in Germany, a conference on architecture theory
entitled “Authenticity” that took place on the
28th of January 2011, in the same tradition as the
previous meetings. However, this conference was
not accompanied by an exhibition, a loss that adds
to the lack of related field trips.
The conferences we participated in were extremely
instructive, covering a wide range of countries
and presenting detailed case studies. The exhi‐
bitions provided a welcomed enrichment of these
meetings and were also useful for networking.
We somehow feel sorry that there were not more
books published to document these conferences
and that the only one documenting the presen‐
tations is not available online. The speakers were
great names in heritage conservation and many
of them are published authors with books on the
restoration projects they presented at the con‐
ference, although sometimes the objects were
the subject of books by other authors. Literature
on conservation of the Modern Movement build‐
ings (figure 9) is generally rare once approaches
are also new. Some time ago these buildings were
still considered not old enough to be part of the
heritage. This was also the reason of the creation
of DOCOMOMO, but still the documentation of the
history of architecture is better represented than
conservation issues in the work of the association
in our opinion. Of course the conference could not
cover all relevant buildings even of the covered
countries and obviously cannot replace the study
trips to see the restored buildings. Perhaps the
future conferences could be held at various loc‐
ations in order to allow in situ visits.
Acknowledgments
We gratefully acknowledge the support of the
Marie Curie Intra‐European Fellowship for the
project CA'REDIVIVUS "Preservation of historic
reinforced concrete housing buildings across
References
[1] B. Burkhard (ed.), Scharoun ‐ Haus Schminke: DieGeschichte einer Instandsetzung, Karl Krämer Verlag,Stuttgart, 2002
[2] R. Kramm and T. Schalk, Sichtbeton, Betrachtungen,Verlag Bau und Technik, Düsseldorf, 2007
[3] S. Pace, M. Rosso, and C. Chiorino, Italia 61: TheNation on Show, Umberto Allemande, Torino, 2006
[4] C. Chiorino, “Structural concrete architecturalheritage, problems and strategies for documentationand conservation. The case study of Turin”, in Proceed‐ings of the 2nd International fib Congress, Naples, 5‐8June 2006, 2006
[5] E. Giacopelli and P. Bonifazio (eds.), Il territoriofuturo. Letture e norme per il patrimonio dell’ archi‐tettura moderna di Ivrea, Umberto Allemandi & C. Edi‐tore, Torino, 2007
[6] P. Bonifazio and E. Giacopelli, Olivetti/Ivrea.
Europe" and of the Marie Curie Reintegration
Grant for the project PIANO "The innovation in
the plan of the current floor: Zoning in blocks of
flats for the middle class in the first half of the
20th century", which helped us to attend the
conferences in 2006‐2009.
Figure 9. Books related to conservation of the heritage ofModern Architecture in Germany, mainly the series Baudenk‐male der Moderne. Photo by M. Bostenaru, 2009.
The News section is publishing diverse
information on cultural heritage topics, such
as on‐site conservation projects reports,
conferences, lectures, talks or workshops
reviews, but also course reviews and any other
kind of appropriate announcements. If you are
involved in interesting projects and you want
to share your experience with everybody else,
please send us your news or announcements.
For more details, such as deadlines and
publication guidelines, please visit
www.e‐conservationline.com
REVIEWS
26 e‐conservation
Cultura di fabbrica e cultura architettonica, EditoreMondadori – Electa, 2010
[7] P. Bonifazio and E. Giacopelli, Ivrea, passato efuturo di una company town, Parametro 262, AnnoXXXVI Marzo/Aprile, 2006
[8] A. Dill, R. Kramm and I. Cerna with C. Engel, T.Mechau and B. Seeland, Vila Tugendhat Brno, Was‐muth, 2008
[9] P. Chareau and B.B. Taylor, Pierre Chareau. De‐signer and Architect, Taschen Verlag, 1998
[10] R. Kramm (ed.), Zum aktuellen Umgang mit denBauten der Moderne: Frankreich, Universität Karlsruhe,Fakultät für Architektur, Institut für Baugestaltung,Baukonstruktion und Entwerfen, Karlsruhe, 2007
[11] M. Edström, Medborgarhuset i Eslöv ‐ Eslöv CivicHall, Arkitektur Förlag, 2007
[12] D. Sharp and C. Cooke, The Modern Movementin Architecture – Selections from the DOCOMOMO re‐gisters, 010 Publishers, Rotterdam, 2000
[13] A. Fairley, De La Warr Pavilion: The ModernistMasterpiece, Merrell Publishers Ltd, 2006
MARIA BOSTENARU DANArchitectural Engineer
Maria Bostenaru Dan (Dipl.‐Ing.) has an engineer‐
ing degree in architecture, specialisation in ur‐
banism, from the Universität Karlsruhe, Germany
(1999). She specialised in the study of risks on
built heritage, seismic retrofit, doing research in
Karlsruhe (Germany), Pavia (Italy) and Bucharest
(Romania).
http://www.googleartproject.com/
GOOGLE ART PROJECT
Google’s last tool has surprised not only art lovers
among the general public but also art historians
and conservators. “Google Art Project” is a direct
and interactive way for anyone to visit one of 17
major art museums in 9 countries for free, without
leaving the comfort of their home. Up to this point,
the museums that have collaborated in this pro‐
ject and agreed to exhibit their galleries online
are Altes Nationalgalerie, The Freer Gallery of Art
Smithsonian, National Gallery (London), The Frick
Collection, Gemäldegalerie, The Metropolitan Mu‐
seum of Art, MoMA, Museo Reina Sofia, Museo
Thyseen – Bornemisza, Museum Kampa, Palace of
Versailles, Rijksmuseum, The State Hermitage Mu‐
seum, State Tretyakov Gallery, Tate, Uffizi and Van
Gogh Museum.
One of the finest features of this project is that
not only it enables the visitor to “walk” through
the museum rooms, in a 360º view, but it also al‐
lows visualising the artworks at incredible zoom
levels. This project promotes easy access to art
but moreover, it offers an important tool for the
study of technical aspects of artworks, a tool that
will prove useful to scholars, teachers, research‐
ers, conservators and many other professionals.
The idea started as part of the “20% project”, the
time that Google allows its engineers to work on
their own initiatives. The Art Project is powered by
their Street View technology and after 18 months
in the making, it the includes 385 gallery rooms
with more than a thousand high‐resolution images
by 486 artists. From these, there are 17 pictures ‐
one from each museum ‐ that are available at su‐
"Explore museums from around the world, discover and view hundreds ofartworks at incredible zoom levels, and even create and share your owncollection of masterpieces"
per‐high resolution, among which "The bedroom"
and "The Starry Night" by Vincent van Gogh,
"In the Conservatory" by Edouard Manet, "The
Nightwatch" and "Return of the Prodigal Son" by
Rembrandt Harmensz van Rijn, to name just a few.
These images are scans with over one gigapixel
in size (over 1 billion pixels), the largest having
more than 12 gigapixels. This introduces a whole
new experience for the viewer who has never had
the possibility to analyse such close ups. As a curi‐
osity, but perhaps deliberate, the painting chosen
for scanning from the National Gallery is "The Am‐
bassadors" by Hans Holbein the Younger (1533).
This painting is world famous by its anamorphic
perspective. It includes a distorted skull that the
viewer can only see correctly while standing in a
certain angle at the right side of the painting.
Of course that nothing can substitute one’s visit
to the museum and the real life experience, but
we must appreciate this great initiative of mu‐
seums to allow us to be a virtual visitor in their
galleries whenever we want.
NEWS
27e‐conservation
THE ORTHODOX CHRISTIAN SAKKOSEcclesiastical Garments Dating from the 15th to the 20th Centuriesfrom the Holy Mountain of Athos
Collection Survey, Scientific Analysis and Preventive Conservation
The sakkos, traditional vestments worn by bishops
of the Orthodox Church, are the object of study
of a recent publication authored by Dr. Christos
Karydis, specialist in textile conservation. The book
is the result of the research of the Euro‐Mediter‐
ranean post‐Byzantine ecclesiastical garments
collection from the Mount Athos, Greece, the most
important monastic centre of the Orthodoxy.
The study includes an overall of 52 sakkoi from 14
monasteries, dating from the 15th to the 20th cen‐
tury, which had never been studied before. The
book offers one of the widest and most complete
views on the sakkoi, from their cultural and historic
significance to their material, stylistic analysis
and conservation state assessment. The import‐
ance of this book is even greater due to the lack
of published literature dedicated to this subject.
The garments were systematically studied by ana‐
lytical techniques, namely Optical Microscopy, HPLC
and SEM‐EDS, for the characterization of different
materials such as fibres, dyes and metal threads,
and for the identification of their degradation
sources. The conservation of this collection is a
major concern for the author who introduced a
new preventive conservation approach for the
care of the collection: the study begins with a dis‐
cussion of the nomenclature, while it addresses the
issue prevalent in Byzantine and post‐Byzantine
research, as to the historical provenance of this
liturgical garment. Different approaches ranging
from art historic and semiotic research to scientific
examination using sophisticated analytical tech‐
niques are applied, in order to introduce a cultural,
historical and technological context of the garments.
Dr. Christos Karydis is researcher and lecturer in
preventive conservation and history of ecclesi‐
astical textiles. He was involved in the protection
of textiles collections from Mount Athos, Jerus‐
alem, Constantinople, Colombia, Spain, UK and
Greece. He is the author of the first book written
in Greek on the preventive conservation of textiles.
The recently published “The Orthodox Christian
Sakkos” is a systematic study of great value not
only to scholars but also to textile conservators
and other museum professionals.
Author: Christos Karydis
Publisher: Archaeopress
Pages: 410 pages with CD‐Rom
Publication date: 2010
ISBN: 9781407307169
Language: English
NEWS
28 e‐conservation
even
ts
The events in this section are linked to the
original homepage of the organisers or to the
calendar of events at www.conservationevents.com.
Click on "Read more..." to find out more details
about each event.
Tools for Prioritizing CollectionCare Print
Date: March 22 Read more...
Place: Birmingham, UK
In all organisations, and especially in cash‐
straitened times, priorities in collection care
have to be established. Organisations have to
choose what is most important to protect and
make available to use and choose which pre‐
servation actions will most effectively achieve
their aim of long‐term access to collections in
libraries and archives. This event looks at a
selection of tools used to establish the prio‐
rities in collection care allowing participants
to consider how the tools could be used in
their own organisations.
Back to the Roots: Workshop onthe Preparation of HistoricalLake Pigments
Date: March 23‐25 Read more...
Place: Munchen, Germany
The workshop is aimed to promote a better un‐
derstanding of the nature, preparation and use
of historical lake pigments, which were relevant
for painting and polychromy. The training will
be targeted at conservator‐restorers, scientists
and art historians who have a special interest
in artist materials, and who wish to deepen
their theoretical and practical knowledge of
the traditional preparation of pigments made
from natural dyestuffs.
Apri
l201
1
1st SAA Symposium
Date: March 30 ‐ April 3 Read more...
Place: Sacramento, California, USA
The Symposium focuses on recent, international advances
in the use of pXRF and other portable, field technologies
for archaeochemical studies of sites in the Americas.
Below the surface of every landscape is chemical evidence
of past human activity and, potentially, an historic site.
Recent advances in the use of portable X‐Ray Fluores‐
cence (pXRF), RAMAN technologies and the reduction in
costs for laboratory analyses have made these technolo‐
gies affordable for field studies that "complete the circle
of understanding" of historic era terrestrial and marine
sites through the integration of archaeochemistry, Ar‐
chaeogeophysics, literature research, oral interviews
and excavation.
Mar
ch20
11
Museums and the Web 2011 (MW2011)The international conference for cultureand heritage on‐line
Date: April 6‐9 Read more...
Place: Philadelphia, Pennsylvania, USA
Museums and the Web is an annual conference exploring
the social, cultural, design, technological, economic, and
organizational issues of culture, science and heritage
on‐line. Taking an international perspective, MW reviews
and analyzes the issues and impacts of networked cultural,
natural and scientific heritage – wherever the network
may reach. The MW community has been meeting since
1997, imagining, tracking, analyzing, and influencing
the role museums play on the Web, and having fun doing
it. MW Program features plenary sessions, parallel ses‐
sions, un‐conference sessions, museum project demon‐
strations, commercial exhibits, mini‐workshops, profes‐
sional forums, two design 'Crit Rooms', and the Best of
the Web awards.
e‐conservation
ART '11: 10th International Conference onNon‐destructive Investigations and Micro‐analysis for the Diagnostics and Conservationof Cultural and Environmental Heritage
Date: April 13‐15 Read more...
Place: Florence, Italy
Non destructive analysis has proved to be the gold stand‐
ard to achieve more successful and long‐lasting preser‐
vation. Many non‐destructive techniques and evaluation
methods applied in the natural sciences offer advantages
to cultural heritage preservation. The synergy between
experts will lead to the continuous development and
adjustments of new scientific methods and their applic‐
ation in the fields of preservation, reconstruction and
diagnostics of museum and archeological objects. The
conference will bring together, in one or the world art
capitals, conservation scientists, curators, art histori‐
ans, architectural researchers and experts in non‐de‐
structive evaluation and material analysis.
Wall Paintings Exposed to OutdoorWeathering
A Conservation Challenge at the World Heritage
Site Constantine Basilica in Trier
Date: April 7‐9 Read more...
Place: Trier, Germany
Using the example of the Constantine Basilica in Trier,
this conference wishes to present the current research
results in order to compile the various difficulties in
preserving outdoor wall paintings. This will be followed
by presentations of other significant case studies and
possible conservation solutions. On the second day, the
major focus will be future methods of in‐situ conserva‐
tion and the conveying of contents, while taking into
consideration potentially conflicting interests of tourism,
monument conservation and art science. The conference
language is German (with translated abstracts).
Apri
l201
1EVENTS
Apri
l201
1
The Science of Objects and Collections
The British Library Conservation ResearchConference 2011
Date: April 11 Read more...
Place: London, UK
This one day conference will explore two linked themes:
understanding the nature of objects, and understanding
the nature of collections. What can we learn about the
behaviour of whole collections by studying individual
objects, and what can we learn about individual objects
by studying whole collections? Topics to be covered in‐
clude the use of spectroscopy and multi‐spectral imaging
to reveal more about the nature of objects, statistical
methods for understanding the nature of collections,
and the influences of the environment on collections.
The full programme is available from the organiser's
website.
Non‐destructive and Microanalytical
Techniques in Art and Cultural Heritage
Date: April 26‐29 Read more...
Place: Berlin, Germany
The aim of TECHNART 2011 is to provide a scientific forum
to present and promote the use of analytical spectroscopy
techniques in the field of cultural heritage. The confer‐
ence builds on the momentum of TECHNART 2009 offering
an outstanding and unique opportunity for exchanging
knowledge on leading edge developments. Cultural herit‐
age studies are interpreted in a broad sense, including
pigments, stones, metals, glass, ceramics, chemometrics
on artwork studies, resins, fibers, forensic applications
in art history, archaeology and conservation science.
The preliminary program will soon be available from the
organiser's website.
30 e‐conservation
arti
cles
AREAS OF PUBLISHING
Conservation TreatmentMural Painting
Painting
Stone
Sculpture
Textiles
Paper / Documents
Photography
Metals
Tile / Ceramic / Glass
Furniture
Music instruments
Ethnographic assets
Archeological objects
Conservation ScienceScientific research
Material studies and characterisation
Analytical techniques
Technology development
Biodeterioration
State‐of‐the‐art
Reviews
Preventive ConservationTheoretic principles
Case studies
Documentation in ConservationStandardisation
Documentation methods
Data management
Conservation TheoryEthics
Conservation History
Art History, Iconography,
Iconology, Chemistry, Physics,
Biology, Photography, Cultural
Management, Museology,
Computer Science, Legislation and
Juridical Processes, Conservation
Policies
and any other field applied to
Conservation and Restoration
of works of art.
Find out more: www.e‐conservationline.com
e‐conservation
INFRARED REFLECTOGRAPHY USING3D LASER SCANNING
By Christian Dietz, Gianluca Catanzaritiand Alfredo Jimeno Martínez
Introduction
Infrared radiation is situated within the electro‐
magnetic spectrum just past the red segment of
visible light and before the microwave region.
Generally, the IR spectrum is divided into IR‐A
(700‐1400 nm, near‐infrared), IR‐B (1400‐3000
nm) and IR‐C (3000 nm ‐ 1 mm). Unlike visible
light, infrared radiation penetrates somewhat in‐
to the layers of a painting, depending upon the
pigments, varnishes and other materials used
during its execution. Backscattered light therefore
contains information about deeper paint layers,
underdrawings and canvas state. In particular,
making visible the compositional sketches, nor‐
mally done using charcoal and applied on the pre‐
paration layer prior to the use of paint, but also
signatures, dates, inscriptions or monograms hid‐
den underneath the painted surface layer, provides
to the professional valuable information that can
help to assign authorship, track back the creational
process and detect changes in the painter's ori‐
ginal intentions (known as "pentimenti") [1].
The first attempts to exploit this technique for
art and restoration purposes began in the 1930s,
when suitable film material became commercially
available. Infrared photography was limited to the
real near‐infrared, a range approximately between
700 nm and 900 nm. Modern infrared reflectography
(IRR), a commonly used and non‐destructive tech‐
nique for the investigation of ancient paintings,
makes use of digital cameras, whose incorporated
CCD sensors are inherently sensitive to infrared
light, in that way images with a wavelength from
800 nm to 2000 nm may be obtained [2].
The instrumental setup of an investigation em‐
ploying IRR is depicted in figure 1.
The best contrast is obtained when opaque pig‐
ments that are transparent for the infrared light,
such as lead white, have been used in the painting.
In this case, the infrared radiation passes through
the pictorial film until it hits either a black carbon
pigment of the underdrawing, where it is absorbed,
or the adjacent ground layer, often made of white
33e‐conservation
SCIENCE AND RESTORATION AT THE SERVICE OF INTERPRETATION
A 3D laser scanning instrument, equipped with an optical transmitter containing a continuous 785 nm
diode laser, was used in order to obtain infrared reflectography data of oil paintings. The investigation
was carried out in two modern oil and acrylic paintings on canvas and a late 16th century panel painting.
In the first case results were compared with existing documentation of the artistic process and in the
second with a previously elaborated study by IR reflectography. Data recording took as short as five
minutes, providing an IR image comparable to those obtained by reflectography in the IR‐A zone of the
spectrum. The technique additionally provides high resolution topographic data of the artworks’ sur‐
rounding, such as frame and adjacent walls, and has potential to be developed into an alternative
method for investigation of pigment layers on virtually any surface, especially if these are of great
dimensions or almost inaccessible.
Figure 1. A typical instrumental setup for IR reflectography.The red lines indicate infrared (IR) while the black linesindicate visible radiation (VIS).
gesso (calcium sulphate), where it is backscattered.
The result is a picture of black areas (absorbed
light) over white background (reflected light).
IRR is nowadays widely accepted and used as a
valuable tool for the investigation of drawing con‐
stituents [3], but can also be applied to obtain
information on pigments on supports other than
canvas or wood, such as mural [4] and cave paint‐
ings [5]. Often, IRR recordings are overlaid to vis‐
ible (VIS) measurements to produce false colour
infrared composites, normally generated by plot‐
ting the green parts of an image as blue, the red
parts as green and the near‐infrared data as red,
providing additional information on pigments, var‐
nishes and binding media. Recent developments
tend to use integrated approaches, such as com‐
bining data obtained by IRR with thermography
[6], X‐ray fluorescence or colourimetry [7].
A main drawback of IRR is the time consumption
necessary for manually mounting many mosaic
pictures, using dedicated software. This is partic‐
ularly true for paintings of great dimension, where
scaffolding has to be constructed for the investi‐
gation in situ, because the camera has to be posi‐
tioned relatively close to the artwork. Accurate x‐y
translation of the painting on a plane perpendicu‐
lar to the camera is also difficult due to geometrical
and photometric distortions. Finally, a uniform
illumination by the lamps is also not always easy
to achieve.
A wide range of laser techniques are nowadays
commonly used for heritage applications [8]. Upon
the laser power applied, they may be divided in
three categories: (a) high power applications that
may be considered somewhat destructive, normally
using Nd:YAG lasers, such as laser ablation for
diagnostic [9], cleaning purposes [10] or laser‐
induced breakdown spectroscopy [11]; (b) others
use moderate laser power but still high enough
to produce excited states of the investigated spe‐
cies, such as Laser Induced Fluorescence [12] or
Raman Spectroscopy [13]; (c) and on the low end
of applied laser power, holographic interferometry
[14] and laser scanning. Laser scanning is nowa‐
days frequently used, typically for producing three
dimensional models of historical sites [15] and
caves [16], or to produce real time topographic
data for documentation of excavations.
The task of such instrument is to assign to each
point reflecting a laser beam within its range of
operation X, Y, Z coordinates, producing a so called
point cloud, which is the raw data for subsequent
modelling. This task can be achieved in two man‐
ners. On one hand a pulsed laser can be employed,
measuring the round‐trip time of the pulse (time‐
of‐flight, TOF), which is the most widely used tech‐
nique for long distance measurements (meters to
kilometres). On the other hand, continuous‐wave
lasers can emit at varying modulation lengths and
detect the phase‐shift of the reflected signal, from
which the distance to the reflecting object can be
calculated. When compared to the TOF technique,
the phase shift technology considerably speeds
up the registration. In our particular case, 120,000
points/second can be achieved with high accuracy,
compared to about 4,000 points/second by TOF,
although this technique is not appropriate for
very long distance measurements such as air‐
borne scanning. Modulated light also allows the
scanner to ignore light from sources other than a
laser, hence interference is substantially reduced.
The scanner works by sending a light beam into
the centre of a rotating mirror. As shown in fig‐
ure 2, the mirror deflects the laser on a vertical
rotation around the environment being scanned.
After interacting with the object, the beam is re‐
flected back into the mirror and the phase shift
of the wave is measured. Using encoders to sim‐
ultaneously record both the mirror rotation and
34 e‐conservation
CHRISTIAN DIETZ, GIANLUCA CATANZARITI & ALFREDO JIMENO MARTÍNEZ
the horizontal rotation of the scanner, X, Y and Z
coordinates of each point can be calculated.
However, phase shift technology is more suscep‐
tible to effects caused by phenomena other than
total reflection of the incoming beam on the sur‐
face to measure. This undesired effect is studied
in the present work in order to obtain infrared
data of painted artworks making use of a three
dimensional laser scanner emitting at 785 nm and
equipped with phase shift detection. Colour infor‐
mation for each scanned data point was simultane‐
ously obtained, making use of a digital camera
coupled to the scan head of the instrument.
Artworks
Studies were carried out on three different paint‐
ings. The first, an oil painting on cardboard covered
with cotton, is a modern interpretation of Melozzo
da Forlì's "Music‐making Angel", by A. Criado Por‐
tal (2010). The second is an untitled work, painted
in acrylic on canvas, showing geometrical forms
with underlying drawing, made with charcoal.
This painting was made in 2009 as a reference
object for IRR studies at the Faculty of Fine Arts
of the Complutense University. The third dates to
the late 16th or beginning of the 17th century and
shows Saint Mark the Evangelist together with
his symbol, the lion. This painting, of unknown
authorship, belongs to the church of Bujarrabal
(Guadalajara, Spain) and is currently being re‐
stored at the Faculty of Fine Arts of the Complu‐
tense University. It is painted on a wooden panel
and attributed to the Castilian School. Figure 3
shows photographs of these paintings.
Instrumental
The 3D laser scanner used was a Faro Photon 80
with software Faros Scene V4.6 for scan control
and data evaluation. Colour option was provided
via a Nikon D300 digital camera with AF Fisheye
35e‐conservation
INFRARED REFLECTOGRAPHY USING 3D LASER SCANNING
Figure 2. Instrumental configuration for a laser scanner withphase shift (∆φ) detection. Legend: 1 ‐ laser diode; 2 ‐ rotatingmirror; 3 ‐ target; 4 ‐ photodiode; 5 ‐ reference oscillator andphasemeter.
Figure 3. Studied artworks and their respective dimensions. From left to right: Music making Angel, 28x33 cm; Untitled, 38x46cm; and Saint Mark the Evangelist, 65.5x89.5 cm.
lenses (Nikkor de 10.5mm 1:2.8G ED), mounted
in horizontal position above the scanning unit.
In order to pinpoint the exact position of the art‐
work under investigation with respect to the instru‐
ment, first a 360º low resolution scan was carried
out. Scans were then taken for selected areas in
full resolution (0,009° vertical, 0,00076° hori‐
zontal) at a recording speed of 120.000 points/
second. Finally, the camera was moved to the
mirror position of the scanner and referenced
optical images were taken.
The instrumental setup used for IRR consisted in
a Hamamatsu InGaAs camera (Mod. C10633‐23),
providing high sensitivity in the wavelength range
from 900 to 1700 nm. The camera was connected
to a real‐time monitor via the standard video out‐
put. Connection to a PC went through a standalone
video image processor (C2741‐62), allowing shad‐
ing correction, contrast enhancement, averaging,
Y‐correction and edge extraction. For image capture,
the paintings were illuminated using two 100 W
halogen lamps.
Results and Discussion
The performance of the instrument matched the
expectations, taking into account the rather li‐
mited part of the IR spectrum under observation.
In general, it can be observed that clear colours
tend to gain transparency and the grey scale be‐
comes uniform, revealing several details which
have been corrected by the painter in the last stage
of the work. In the picture of the angel, a white
pearl, initially forming part of the ornamental
headband worn by the angel, but finally over‐
painted, can be clearly distinguished, as shown in
figure 4. In the centre of the same figure, in the area
just above the marked arrow, tracing details of the
angel’s hairstyle which have also been slightly
changed in the final version can be appreciated.
The same applies to the eyebrow and horizontal
diameter of the angel’s eye, which appear to have
different angles and size, respectively, when com‐
pared to the finished work.
However, charcoal sketches drawn directly onto
the support lack sufficient resolution and have
to be more deduced than detected, as shown in
figure 5, in the example of the untitled picture.
In this case, the underdrawing shows a sitting
man with head and beard, which can be clearly
distinguished in the reflectography image. In con‐
trast to that, the inner light and dark orange col‐
oured geometrical figures of the original have not
become completely transparent in the scanned
image, in particular the darker one, superimpos‐
ing the underlying drawings. This is not surprising
as penetration depth of infrared radiation increases
with growing wavelength. Obrutsky et al. presented
a very illustrative example for this fact [17], where
a picture showing a horse head was subsequently
investigated in the visible, IR‐A, IR‐B and IR‐C
region. The longer the wavelength, the clearer two
horses in the background could be distinguished,
which formed part of the original painting but were
finally overpainted by the artist. Nonetheless,
the first traces of the charcoal drawings, such as
the lower border of the left arm and other features
delimiting the figure, already appear using near
infrared light, as shown at some details highlighted
in figure 5A.
Hence, it is desirable to dispose of alternative
laser wavelengths, for example at 1400 nm and
36 e‐conservation
Figure 4. Comparison of IR (left) and VIS (right) images. Thearrow indicates a pearl which is not part of the final design.
CHRISTIAN DIETZ, GIANLUCA CATANZARITI & ALFREDO JIMENO MARTÍNEZ
2200 nm, for which suitable laser diodes are avail‐
able. Necessary changes within the laser head
would be relatively easy to achieve, for instance
by a movable mirror focusing light emitted by the
additional diodes into the optical path of the ori‐
ginal. From the detector side the issue is a bit more
complicated, as the phasemeter has to be set to
the changing wavelength, which possibly may be
done by hardware changes and/or corresponding
software correction algorithms.
Taking into account the instrument’s current re‐
striction to a specific wavelength in the real near
infrared region (785 nm), the gained information
is still highly valuable, although not as complete
as an IRR image, which covers the whole infrared
region.
This may be highlighted with a comparison of scan
and IRR data obtained from the painting of Saint
Mark the Evangelist. The underlying sketches,
37e‐conservation
Figure 5 (above). Detail of scanned (A) and IR reflectography (B) image on the untitled painting. In the first image, the uppercircle contains a hat, the middle circle shows a right hand supporting the head, the lower circle has a left elbow, the oblique lineshows a right arm, and the rectangle contains some horizontal lines.
Figure 6 (below). Colour photography (A), scanned (B) and reflectography image (C) of the lion belonging to the painting ofSaint Mark the Evangelist.
A B
A B C
INFRARED REFLECTOGRAPHY USING 3D LASER SCANNING
probably done in oil paint rather than charcoal,
reflect almost entirely the final composition of
the painting, outlining the figures and landscape
which were later on filled with colour. Looking
into the reflectography data, this becomes par‐
ticularly evident in zones like the hand of the
saint holding the paint brush and the clothing
he wears (data not shown). As it can be seen in
figure 6, showing a detail of the lion, Saint Mark’s
symbol, situated in the lower left corner of the
panel, generally the more profound paint layers,
such as traces of the forehead of the animal, can
be distinguished more clearly making use of the
IRR image. In turn, details of the superficial paint
layers, such as the final touches to improve the
appearance of the eyes, can be more clearly ap‐
preciated in the near infrared zone, correspond‐
ing to the scanned image, as shown in figure 7.
The ultimate compositional features, such as li‐
on’s beard, can be confirmed by both methods,
as the last paint layers are the first to become
transparent using infrared light.
The only problem encountered during data record‐
ing is the total reflection of the IR beam, occur‐
ring to a certain amount when hitting the painting
close to the right angle, causing plain white zones
in the image. To overcome this, the artwork has
to be situated slightly above or below the optical
path of the scan head.
The laser scanner used splits the beam into 3 com‐
ponent parts, operating on 3 different modula‐
tion lengths, providing an accuracy of 0.58 mm
within the specific range of the measured target,
with a vertical and horizontal resolution of 0.009º
and 0.00076º, respectively. These can be considered
to be very good values for a middle range scanner,
nonetheless not enough to reveal very fine details
of a painting’s topography, such as brush strokes.
Furthermore, an additional imprecision is intro‐
duced just by the fact that the used IR radiation
penetrates into the investigated surface. Nonethe‐
less, a high resolution 3D model of components
such as the frame or, in case the artwork is in‐
vestigated in its original location (e.g. church,
cathedral, castle) the paintings’ adjacent sur‐
rounding, as well as topographic data in case of
cave paintings, can be easily obtained from the
point clouds recorded during scanning.
A final issue which may be discussed here is the
total amount of radiation to which the painting
has to be exposed during the analysis. It is well
known that incident light causes ageing processes
in pigments and binding media, reason for which
preservation of artworks, in particular old and
highly valuable pieces always require the limita‐
tion of light exposure to a minimum.
The measure of the total power of electromagnetic
radiation landing on a particular surface, including
infrared, ultraviolet, and visible light, is defined
as irradiance, a quantity for which the SI unit is
Watt per square meter. The exact calculation of
this value for a given light source is not an easy
task, but with some simplifications one may get
a good estimate of its dimension. Assuming that
the source is emitting at a particular wavelength,
that neither absorption nor refraction of light oc‐
curs in the medium and that the magnetic suscep‐
tibility is negligible, irradiance simply decreases
with the square of the distance from the source.
This is because the overall power is constant but
the illuminated area grows squared with distance.
38 e‐conservation
Figure 7. Detail of the lion’s right eye obtained by scannedimage (left) and IR reflectography (right).
CHRISTIAN DIETZ, GIANLUCA CATANZARITI & ALFREDO JIMENO MARTÍNEZ
In the case of a directional laser beam, the problem
is that the radiation does not distribute uniformly
in all directions. During scanning, most of the time
a given point at the surface does not receive any
energy at all, but a high energy over a short frac‐
tion of time, resulting in a low average irradiation
but with punctual higher values. The average ra‐
diant emittance value for an object situated at a
given distance from the scanner may hence be
calculated as:
I ⋲ P / 4 π d2
where P is the power of the light source and d the
distance. In our particular case the laser power is
22 mW and the distance to the artwork was set to
about two meters, obtaining an irradiance value
of 0.44 mW/m2. For calculation of short term ex‐
posure, we have to use the laser beam diameter,
which is, following the manufacturer specifications,
a circular spot of about 3 mm diameter at exit.
Here we calculate an irradiance of more than 3000
mW/m2, which is a bit more than the double of sun‐
light intensity. This peak value will be achieved for
the spot area over which the beam passes no longer
than the maximum pulse duration of the laser, which
is at full resolution 0.0076 seconds only and de‐
creases proportionally with the resolution.
Tungsten halogen incandescent lamps, as those
commonly employed for illumination in IRR, are
thermal radiators, which means that light is gener‐
ated by heating a solid filament to high tempera‐
tures. Assuming that the spectral power distribu‐
tion roughly follows that of a blackbody radiator,
up to 85 percent of the emitted energy lies in the
infrared region of the spectrum, another 15‐20
percent falls into the visible and about 1 percent
into the ultraviolet wavelengths. The total radi‐
ation follows a fourth power law with respect to
the tungsten wire temperature, which means that
increasing temperature shifts the spectral distri‐
39e‐conservation
bution into the visible region of the spectrum, the
area under the resulting bell shaped curve rep‐
resents the total irradiance.
Under ideal conditions and for the aforementioned
distance, for a 100 W halogen bulb we would achieve
an irradiance of 2000 mW/m2 for the total incident
electromagnetic radiation, spanning the wave‐
length region between 200 and 3000 nanometres.
Though heat dissipation in air would considerably
diminish the real irradiance in the example, in
practice these lamps have to be situated much
closer to the artwork when taking reflectography
images, while the scanner may be placed as far as
ten meters from the object without losing much
of resolution. Furthermore, one has to consider
that the spectrum emitted by incandescent lamps
has a considerable amount of light with wave‐
lengths shorter than infrared, which in general is
considered to cause more damage to the artwork.
This is particularly true for darkening of yellow pig‐
ments such as chrome yellow [18], where exposure
to UV‐light causes superficial reduction of the origi‐
nal Cr(VI) to Cr(III). Possibly the most important
factor when comparing both techniques is the total
exposure time to light, ranging from tenths of
minutes for taking mosaic pictures in IRR to the
duration of a laser pulse when making use of scan‐
ning technology.
Hence, peak values are in the same order of mag‐
nitude for this given example, but for total irra‐
diance, the values obtained for the scanner are
about three orders of magnitude lower.
Conclusions
A direct comparison of infrared reflectography
versus a 3D laser scanning device for investiga‐
tion of artworks revealed that both provide com‐
parable information in the near‐infrared region.
For the mid and far‐infrared regions, revealing
information of deeper paint layers such as the un‐
INFRARED REFLECTOGRAPHY USING 3D LASER SCANNING
e‐conservation40 e‐conservation
derdrawing, IRR appears to be the more suitable
method, since the laser diodes emission is limited
to a well defined wavelength in the NIR zone.
Nonetheless, the scanning technology provides
several advantages over classical IRR as coloured
and fully measurable 2 or 3D models can be achieved
within minutes, even though further modelling,
for instance surface topographic analysis and rep‐
resentation, requires additional manpower and
computing time. False colour IR pictures are also
available, using scan data post‐processing in
dedicated software. The technique is especially
suitable for paintings of great dimensions and
with difficult accessibility, as it can be operated
from a considerable distance to the object and
does not require mounting additional structures,
such as a scaffold.
Peak values of light irradiation may be considered
to be in the same order of magnitude for both
techniques, but much longer exposure times are
necessary in case of incandescent lamps, which
contrary to the laser, emit a considerable portion
of more energetic and hence more harmful light.
On the other hand, the overall irradiance for the
laser technique is orders of magnitude lower.
The technique has clearly shown potential to be
developed into a competitive instrument with re‐
spect to IRR. This could be relatively easy to achieve
by the incorporation of laser diodes emitting in
the mid and far‐infrared region into the laser head
and the corresponding soft‐ and hardware changes
on the detector side.
Acknowledgments
We would like to thank Consuelo Dalmau and Silvia
García Fernández‐Villa, from the Department of
Painting and Restoration of the Faculty of Fine
Arts, Complutense University, for facilitating the
access to most of the investigated artworks and
helping with the reflectography raw data. Antonio
Criado Portal is gratefully acknowledged for pro‐
viding original artwork and the corresponding doc‐
umentation of the creation process. Thanks to Val‐
entín Garcia Baonza for the fruitful discussions and
advice regarding infrared emitting laser systems.
References
[1] F. Casadio, and L. Toniolo, “The analysis of
polychrome works of art: 40 years of infrared
spectroscopic investigations”, Journal of Cultural
Heritage 2(1), 2001, pp. 71‐78, doi:10.1016/
S1296‐2074(01)01107‐4, URL
[2] D. Saunders, R. Billinge, J. Cupitt, N. Atkinson,
and H. Liang, “A New Camera for High‐Resolution
Infrared Imaging of Works of Art”, Studies in Con‐
servation 51, 2006, pp. 277‐290
[3] M. Attas, E. Cloutis, C. Collins, D. Goltz, C.
Majzels, J.R. Mansfield, and H.H. Mantsch, “Near‐
infrared spectroscopic imaging in art conservation:
investigation of drawing constituents”, Journal
of Cultural Heritage 4(2), 2003, pp. 127‐136,
doi:10.1016/S1296‐2074(03)00024‐4, URL
[4] F. Ospitali, A. Rattazzi, M.P. Colombini, A.
Andreotti, and G. di Lonardo, “XVI century wall
paintings in the “Messer Filippo” cell of the tower
of Spilamberto: Microanalyses and monitoring”,
Journal of Cultural Heritage 8(3), 2007, pp. 323‐
327, doi:10.1016/j.culher.2007.02.004, URL
(available at URL [pdf])
[5] G. Verhoeven, “Imaging the invisible using
modified digital still cameras for straightforward
and low‐cost archaeological near‐infrared pho‐
tography”, Journal of Archaeological Science
35(12), 2008, pp. 3087‐3100, doi:10.1016/
j.jas.2008.06.012, URL
CHRISTIAN DIETZ, GIANLUCA CATANZARITI & ALFREDO JIMENO MARTÍNEZ
[6] D. Ambrosini, C. Daffara, R. Di Biase, D. Paoletti,L. Pezzati, R. Bellucci, and F. Bettini, “Integratedreflectography and thermography for woodenpaintings diagnostics”, Journal of Cultural Heritage11(2), 2010, pp. 196‐204, doi:10.1016/j.culher.2009.05.001, URL
[7] A.C. Felici, G. Fronterotta, M. Piacentini, C. Ni‐colais, S. Sciuti, M. Vendittelli, and C. Vazio, “Thewall paintings in the former Refectory of the Trinitàdei Monti convent in Rome: relating observationsfrom restoration and archaeometric analyses toAndrea Pozzo’s own treatise on the art of muralpainting”, Journal of Cultural Heritage 5(1), 2004,pp. 17‐25, doi:10.1016/j.culher.2003. 07.001, URL
[8] M. T. Doménech‐Carbó, “Novel analytical meth‐ods for characterising binding media and protec‐tive coatings in artworks”, Analytica Chimica Acta621(2), 2008, pp. 109‐139, doi:10.1016/j.aca.2008.05.056, URL
[9] B. Giussani, D. Monticelli, and L. Rampazzi,“Role of laser ablation–inductively coupled plasma‐mass spectrometry in cultural heritage research:A review”, Analytica Chimica Acta 635(1), 2009,pp. 6‐21, doi:10.1016/j.aca.2008.12.040, URL
[10] A.V. Rode, K.G.H. Baldwin, A. Wain, N.R. Mad‐sen, D. Freeman, Ph. Delaporte, and B. Luther‐Davies, “Ultrafast laser ablation for restorationof heritage objects”, Applied Surface Science254(10), 2008, pp. 3137‐3146, doi:10.1016/j.apsusc.2007.10.106, URL
[11] M. Brai, G. Gennaro, T. Schillaci, and L. Tran‐chita, “Double pulse laser induced breakdownspectroscopy applied to natural and artificialmaterials from cultural heritages: A comparisonwith micro‐X‐ray fluorescence analysis”, Spectro‐chimica Acta B 64(10), 2009, pp. 1119‐1127,doi:10.1016/j.sab.2009.07.027, URL
[12] V. Raimondi, G. Cecchi, D. Lognoli, L. Palombi,
R. Grönlund, A. Johansson, S. Svanberg, K. Barup,and J. Hällström, “The fluorescence lidar tech‐nique for the remote sensing of photoautotrophicbiodeteriogens in the outdoor cultural heritage:A decade of in situ experiments”, InternationalBiodeterioration & Biodegradation 63(7), 2009,pp. 823‐835, doi:10.1016/j.ibiod.2009.03.006,URL
[13] D. Creagh, A. Lee, V. Otieno‐Alego, and M.Kubik, “Recent and future developments in theuse of radiation for the study of objects of culturalheritage significance”, Radiation Physics andChemistry 78(6), 2009, pp. 367‐374, doi:10.1016/j.radphyschem.2009.03.005, URL
[14] V. Tornari, "Laser interference‐based tech‐niques and applications in structural inspectionof works of art", Analytical and Bioanalytical Chem‐istry 387(3), 2007, pp. 761–780, doi: 10.1007/s00216‐006‐0974‐4, URL
[15] P. Martín Lerones, J. Llamas Fernández, Á.Melero Gil, J. Gómez‐García‐Bermejo, and E. Za‐lama Casanova, ”A practical approach to makingaccurate 3D layouts of interesting cultural herit‐age sites through digital models”, Journal of Cul‐tural Heritage 11(1), 2010, pp. 1‐9, doi:10.1016/j.culher.2009.02.007, URL
[16] J. Luis Lerma, S. Navarro, M. Cabrelles, andV. Villaverde, “Terrestrial laser scanning and closerange photogrammetry for 3D archaeologicaldocumentation: the Upper Palaeolithic Cave ofParpalló as a case study”, Journal of Archaeolo‐gical Science 37(3), 2010, pp. 499‐507, doi:10.1016/ j.jas.2009.10.011, URL
[17] A.E. Obrutsky and D. Acosta, “Infrared reflec‐tography, an NDT technique for images diagnosis”,presented at the 3rd Pan American Conference forNondestructive Testing ‐ PANNDT, Rio de Janeiro,Brazil, June 2‐6, 2003 (available in Spanish atURL [pdf])
INFRARED REFLECTOGRAPHY USING 3D LASER SCANNING
41e‐conservation
[18] L. Monico, G. Van der Snickt, K. Janssens, W.
De Nolf, C. Miliani, J. Dik, M. Radepont, E. Hendriks,
M. Geldof, M. Cottez, "Degradation Process of Lead
Chromate in Paintings by Vincent van Gogh Studied
by Means of Synchrotron X‐ray Spectromicroscopy
and Related Methods. 2. Original Paint Layer Sam‐
ples", Analytical Chemistry 83, 2011, pp. 1224–
1231, doi:10.1021/ac1025122, URL
CHRISTIAN DIETZContact: [email protected]
Christian Dietz received his MSc from Technische
Hochschule Darmstadt in 1995. Then he moved
to Complutense University of Madrid, where he
obtained his PhD in Chemistry in 2001. The fol‐
lowing 7 years of investigation, at the Department
of Analytical Chemistry, were mainly devoted to
instrumental and method development in metal
speciation analysis, with a special focus on sample
treatment, but as well bio‐environmental studies
in general and waste water management in par‐
ticular. In 2008 he was involved in the establish‐
ment of the Centre for Archaeometry and Archae‐
ological Analysis at the Complutense University
of Madrid, where he currently works dedicated to
instrumental analysis and dating of a wide range
of archaeological artefacts. He also covers non
invasive survey techniques in archaeology such
as geophysical prospections and laser scanning.
GIANLUCA CATANZARITIContact: [email protected]
Gianluca Catanzariti received his MsC in Geolo‐
gical Science from the Universitá degli Studi di
Torino (Italy) in 1999. Currently he is working on
his PhD thesis centred on archaeomagnetic meas‐
urements at the Faculty of Physics, Dpt. of Earth
Sciences at the Complutense University of Madrid.
At the same time he is employed as technician at the
universities Centre for Archaeometry and Archae‐
ological Analysis, where is is mainly devoted to
geophysical prospection methods such as ground
penetrating radar, a field where he also holds years
of experience at an Italy based private company.
Further, he is a specialist in archaeomagnetic
dating techniques and was actively involved in
the establishment of the paleosecular calibration
curve for the Spanish Peninsula.
ALFREDO JIMENO MARTÍNEZContact: [email protected]
Alfredo Jimeno received his higher education in
History and Archaeology at the University of Zar‐
agoza, where he obtained his PhD in 1981. His
teaching and research activities started in 1976
at the College of Soria (University of Zaragoza),
moving to the Complutense University of Madrid
in 1986. He was appointed Director of the Centre
for Archaeometry and Archaeological Analysis at
the same university in 2007. His extensive research
activities, embodied in a dozen books and over 150
articles, focus on the early history of the Spanish
Central Plateau, covering the Bronze Age, Iron Age
and the Romanization. His work at international
level is reflected in the joint management of dif‐
ferent projects on "The origin of food production
in the Blue Nile area”, as a member of the Archae‐
ological Mission of the Complutense University in
Sudan (1988‐1999) and he is correspondent of the
German Archaeological Institute. Currently, he is
a member of the Scientific Committee of “Duques
de Soria” foundation and of the Editorial Board of
the U.C.M. “Complutum” magazine. In 2005 he was
appointed Commissioner for the International
Exhibition "Celtiberians”, organised by the Junta
de Castilla y León, entity which also named him
director of the site management plan for Numancia
(1994‐present).
CHRISTIAN DIETZ, GIANLUCA CATANZARITI & ALFREDO JIMENO MARTÍNEZ
42 e‐conservation
A REFLECTION ON THE PREVENTIVECONSERVATION OF ARCHAEOLOGICAL WOOD
AND THE EFFECTS OF MASS TOURISM
The Case Study of the Vasa Warship
By Cristina Cabello‐Briones
Introduction
Tourism is and must be acceptable for any museum.
However, large‐scale tourism has a direct nega‐
tive effect on collections such as that of the Vasa
Museum. Although it is clear that environmental
conditions affect archaeological wood, preventive
conservation of such collections has not been ex‐
tensively considered. Wooden shipwrecks have
been studied from several perspectives mainly in
research that refers to material degradation and
new treatments. The main objective of this article
is to raise public awareness of this topic and high‐
light the benefits of a well planned preventive
conservation strategy in order to safeguard ar‐
chaeological wooden cultural artefacts. Before
analysing the example of the Vasa Museum, a
brief description of the effects of environment
and tourism on archaeological wood and an in‐
troduction to preventive conservation manage‐
ment are presented.
Preventive Conservation of Archaeological Wood
Wood equilibrates with its environment. If the sur‐
rounding conditions change, wood reacts to the
abundance or absence of moisture in the air and
will expand or contract. Thomson [1] recommen‐
ded 19‐24 °C and 45‐55% RH as ideal conditions
for the museum environment housing unpainted
wooden objects. At lower RH values, wood cracks,
becomes brittle and shrinks. Above 65% RH, mold
growth is promoted and swelling increases. Main‐
taining the relative humidity between 50‐60%
reduces most of the visible damage. However, Mi‐
chalski [2] reminds us that "the specifications for
temperature and humidity in related literature rep‐
resent the lowest common denominator amongst
the needs of objects, and not necessarily the op‐
timum for each". Each case needs to be analysed
individually and on many occasions this means
testing the decisions in practice.
When an object is mechanically stable, most dam‐
age is due to RH fluctuations. These can eventu‐
ally lead to cracking, checking and warping of the
wooden artefact. In addition, fast changes in rel‐
ative humidity cause internal stresses due to dif‐
ferences of moisture between inner and outer
areas [3, p. 34]. Therefore, an ideal environment
is achieved when no cyclic variations occur. Slight
shifts are permitted if the change is slow, varying
at maximum over ±5% range [4, p. 269].
Relating to temperature, every 10 °C increase
doubles the average rate of organic reactions [3,
p. 40]. Therefore, lower temperature levels (15‐
20 °C) slow these rates and offer a comfortable
environment to visitors.
Light affects wood in several ways. The most severe
damages are connected with chemical bond break‐
age, free radical formation and the subsequent
depolymerisation of polymers. In addition, wood
44 e‐conservation
Archaeological wood is an organic material, sensitive to environmental conditions. Wood, even when
treated with polyethylene glycols, adapts to the surrounding environment with physical and chemical
reactions that may be detrimental to its preservation. In addition, excessive tourism has a negative
effect on the museum environment once its indoor conditions fluctuate directly with the number of visitors.
In order to minimize the effects of a negative climate caused by mass tourism on archaeological wood
collections, preventive conservation measures should be taken. To illustrate an effective preventive
conservation management, the case of the Vasa museum in Stockholm, which houses the 386 years old
Vasa warship, is discussed.
CRISTINA CABELLO‐BRIONES
that has been exposed to the visible and ultra‐
violet wavelengths radiation of daylight under‐
goes colour change [5]. Experts agree on a range
between 300 and 50 lux as appropriate for safe
display, although lighting between 200 and 50 lux
should be used for severely deteriorated objects
considering that 50 lux is the minimum level re‐
quired for colour perception and adequate visi‐
bility [4, p. 268].
Treatment with polyethylene glycol (PEG) has be‐
come the most common application for the pre‐
servation of many kinds of waterlogged wooden
remains. The technique involves the impregnation
of wood with PEG solutions so that the water in the
cell walls is replaced by the preservative. The pro‐
cess is focused on the stabilisation of the timbers’
dimensions and bulking of the wood structure.
Highly degraded wood treated with PEG changes
its dimension regularly according to the relative
humidity though its range of change is smaller
than that of sound wood [6]. For wood treated
with any molecular weight of PEG, unless it is con‐
tinually recoated, exposure to high RH (higher
than 60%) will make the surface sticky and could
leach out the impregnant [7]. In addition, PEG is
hygroscopic and transports ions and dissolved
oxygen within the treated wood when there are
humidity fluctuations causing both physical and
chemical problems [8].
Impact of Large‐scale Tourism on the CulturalHeritage
Tourism affects tangible heritage in several and
diverse ways: visitors release heat, water vapour
and carbon dioxide; they transport external par‐
ticles and the accumulation of dust can lead to
further cleaning that may damage surfaces; they
also generate turbulence, which increases the
deposition rate of particulate matter [9, pp. 127‐
140]. In addition, a large number of people visit
museums on rainy days and their wet coats intro‐
duce additional moisture.
Although it is difficult to differentiate between in‐
door environmental variations caused by visitors and
the effects of outdoor climate, it is clear that the
way tourism in museums is organised nowadays
has a direct connexion with environmental fluctu‐
ations. An adult releases approximately 60 grams
of water vapour per hour and 60 watts per square
metre of body surface as heat [10, p. 20], affecting
ambient relative humidity. Negative environmental
condition cycles are related to successive waves
of tourists who access the museum. For example,
measurements in the Kunsthistorisches Museum
in Vienna during and after the Bruegel exhibition
in 1998 showed an increase in heat and moisture
directly caused by the tourism flows [9, p. 132].
To avoid the collection itself and/or the building
acting as buffer elements, environmental control
systems must cope with these sudden stresses,
maintaining a constant climate during and after
the visiting hours.
Preventive Conservation Management
Although large‐scale visitor access involves risk
for cultural objects, the public is necessary to
keep a museum open. A large number of visitors
increases the prestige of a museum and ensures
funding as demonstrated by the Delphi survey of
owners and managers of historic properties across
the United Kingdom [11]. The survey shows that
the highest ranked criterion for priority in fund‐
ing is related to the ‘significance’ of the heritage.
This is measured through its uniqueness and rel‐
evance for the community as well as its public
appeal. However, pressures imposed by visitors
are not considered to be a major criterion for de‐
termining conservation funding.
45e‐conservation
PREVENTIVE CONSERVATION OF ARCHAEOLOGICAL WOOD
Mass tourism is an economic resource and in the
context of indoor climate, the key is to achieve the
right balance between the increasing demand for
access and the need to protect the cultural herit‐
age itself.
Different measures can be carried out to reduce
the impact of tourism. Not including the cultural
object/site in promotional material could reduce
the awareness of the attraction [12]. Another
solution could be to display the most valuable
objects of a collection in showcases or substitute
them with replicas. However, display cases are
not always the best conservation solution [13]
and ethical issues as authenticity, provenance
and context could arise [14]. According to Young
and Cassar [15], the type of measure depends on
the uniqueness and vulnerability of the cultural
artefact, its local or international importance,
the ability to make facsimiles, the rate of degrada‐
tion from environmental conditions and the quality
of the protective environment.
In these days of rising cost and lack of funding,
preventive conservation management is the best
option. According to Cassar’s definition, preventive
conservation management is “the creation and
maintenance of an environment that limits the
decay of museum objects to the absolute minimum
consistent with public access” [10, p. 3]. A pre‐
servation plan allows the analysis of deteriorating
environmental conditions caused by the influx of
tourist and developing a strategy to protect the
cultural artefacts. Additionally, environmental
monitoring is a reliable source of information that
can be used to assess risks and understand dam‐
ages and impacts.
Case Study: Preventive Conservation of theVasa Warship
The Swedish King Gustavus Adolphus ordered the
Vasa (figure 1) to be built in 1625 due to the Thirty
Years' War. Although a number of different tree
species were used in the Vasa, 90% of the weight
46 e‐conservation
CRISTINA CABELLO‐BRIONES
Figure 1. The Vasa warship. Photo by Anneli Karlsson, the Swedish National Maritime Museums, © All rights reserved.
47e‐conservation
Figure 2. Stern view of the Vasa warship. Photo by Karolina Kristensson, the Swedish National Maritime Museums,© All rights reserved.
PREVENTIVE CONSERVATION OF ARCHAEOLOGICAL WOOD
of the hull is oak. The ship sank, fully equipped, on
its maiden voyage out of Stockholm harbour in
1628, and was raised to the surface in 1961. On
the salvage, the timbers were found to be in re‐
markably good state (figure 2). The main reasons
were the absence of marine borers, fungi and rot
due to the near oxygen‐free conditions in the wa‐
ter and high concentration of hydrogen sulphide.
However, the surface of the timbers was attacked
by cellulose‐degrading and sulphur‐meta‐bolizing
microorganisms. After salvage, exposure to atmo‐
spheric oxygen initiated a multitude of chemical
reactions threatening the long‐term preserva‐
tion of the ship such as oxidation of sulphur to
sulphuric acid, red‐ox reactions of sulphur and
iron compounds from bolts and cargo made of
iron, free radical reactions, acid hydrolysis and
oxidative degradation reactions of cellulose. The
conservation with PEG 1500 and 600 between 1962
and 1979 was followed by an air drying process for
another ten years1.
According to Emma Hocker [16, p. 4], conservator
at the Vasa Museum, the control of the indoor
environment has been a challenge, especially
due to the increasing public. The museum was
designed as a display case for the ship (figure 3)
with an internal airspace of about 105000 m3. The
original predictions of 600 000 visitors per year
have steadily increased until numbers reached 1.2
million visitors in 2008. The main reasons are its
value as source of information of a specific con‐
text and timeframe, but also the museum market‐
48 e‐conservation
Figure 3. General view of the Vasa Museum. Photo by Åke E:son Lindman, © All rights reserved.
CRISTINA CABELLO‐BRIONES
1 More detailed information can be found on the website ofthe Vasa Museum website at: http:// www.vasamuseet.se/en/Preservation‐‐Research/
by dehumidifying in advance when potential risks
are detected [16, p. 7]. Also a new energy‐effect‐
ive halogen‐based lighting system was installed
producing 30% less radiant heat [21].
Since installation, the hall climate has stabilised
considerably despite the greater number of visit‐
ors and the outdoor climate (figures 5 and 6). Out‐
breaks are not worsening either in coverage or
pH value and the almost 10% RH gradient over
the height of the ship was halved immediately
[16, p. 7].
ing strategy and the rise in the number of cruises
with Stockholm as a destination.
The museum former climate specifications were
set at 60% RH and 20 °C for summer months, and
57.5% RH and 17 °C in winter to avoid condensa‐
tion in the museum walls [17], equivalent to wood‐
moisture content of 10‐12%. Although this system
was sufficient for the winter months [18, p. 171]
when there were relatively few visitors, during
warm and wet summers, the RH rose to over 65%.
Temperature and RH gradients caused by the build‐
ing height [16, p. 5] were accepted as inevitable
but at lower levels [19] the RH at times reached
70% impacting the movement of the wood. The
climate system was under‐dimensioned.
After a record number of visitors during the rainy
summer of 2000, salt outbreaks were drawn to the
surface. Hydrated PEG could have dissolved salts
[20] from the material at high RH and these salts
could have precipitated on the wood surface when
the PEG was dehydrated at low RH. In addition,
large fluctuations were recorded near the entrance
to the museum shop and restaurant, where un‐
conditioned air could enter without control, and
in the viewing galleries at the stern, where stronger
lighting and visitors were concentrated [16, pp. 5‐
6]. It was then decided to reduce the RH from 60%
to 55% ± 4% and the year‐round temperature to
18.5 ± 1.5°C, equivalent to 10% moisture content
in the wood [16, p. 6].
In 2004, a new climate system with increased ca‐
pacity and sensitivity was installed in the ship hall
(figure 4). The principle is based on conditioned
air pumped in at low levels, rising around the ship
and sucked out through a duct near the ceiling
[18, p. 173] providing a protective curtain around
the ship. In addition, the visitor counter at the
museum entrance was incorporated into the steer‐
ing parameters. This measure allows preparation
49e‐conservation
Figure 4. Current climate‐control system above the ship stern.Photo by Karolina Kristensson, © All rights reserved.
Figure 5. Thermo‐hygrograph chart of the Vasa generated fromthe climate‐control system data at the Vasa Museum betweenthe 16th of June and the 21st of September 2003. The environ‐mental fluctuations were remarkable. Source: the Swedish Na‐tional Maritime Museums, © All rights reserved.
PREVENTIVE CONSERVATION OF ARCHAEOLOGICAL WOOD
However, this system could operate at maximum
capacity if the museum gives in to the pressure
of the long queues of visitors in peak season and
allows more public at one time. Then, a stable cli‐
mate could not be guaranteed [16, pp. 8‐9].
Conclusions
Ships that have been rescued from the sea are
among the most popular attractions worldwide,
making maritime museums highly profitable.
The great popularity of these museums ensures
continued funding for research, conservation,
acquisition and promotes cultural tourism. How‐
ever, it also increases the pressure to allow greater
numbers of visitors, making it difficult to maintain
a suitable preventive conservation programme.
Large‐scale tourism has a direct negative effect
on museum indoor climate environments. It pri‐
marily affects relative humidity causing rapid
fluctuations in short periods of time. Variations
in moisture enable the migration of water, dis‐
solved oxygen and salts into the PEG and wood,
and will initiate different chemical reactions.
The general concern nowadays is that the control
of relative humidity and temperature is the most
feasible preventive conservation measure in mu‐
seums with archaeological collections and high
tourism. Stabilizing the environment, avoiding
damaging extremes and fluctuations and main‐
taining the relative humidity low (around 55%)
will help preserve PEG treated marine wooden
artefacts [22].
Every museum should develop an environmental
management programme, a carefully elaborated
long‐term maintenance plan. This could include
technical aspects, such as dealing with monitor‐
ing and controlling of the museum environment,
and organisational issues, such as a visitor man‐
agement plan.
Acknowledgments
I wish to acknowledge the Vasa Museum. Special
thanks to Emma Hocker for generously giving me
part of her time to share her experience and know‐
ledge.
50 e‐conservation
Figure 6. Thermo‐hygrograph chart of the Vasa generated from the climate‐control system data at the Vasa Museum from the 16th
of June to the 21st of September 2009. RH and temperature fluctuations were minimized. Source: the Swedish National MaritimeMuseums, © All rights reserved.
CRISTINA CABELLO‐BRIONES
51e‐conservation
References
[1] G. Thomson, The Museum Environment, Butter‐
worths, London, 1981, p. 85
[2] S. Michalski, “Temperature and Relative Humidity:
the definition of correct/incorrect values”, in S.
Michalski (ed.), A Systematic Approach to the Con‐
servation (Care) of Museum Collections, Canadian
Conservation Institute, Ottawa, Ontario, 1992, ap‐
pendix D, p. 2
[3] B. Appelbaum, Guide to Environmental Protec‐
tion of Collections, Sound View Press, Boston, 1991
[4] V. Jessen and C. Pearson, “Environmental con‐
ditions for storage and display of marine finds”,
in C. Pearson (ed.), Conservation of Marine Ar‐
chaeological Objects, Butterworths, London,
1987
[5] R. Harvey and C. Freedland, “Exhibition and
Storage of Archaeological wood”, in R. M. Rowell
and R. J. Barbour (eds.), Archaeological Wood: Prop‐
erties, Chemistry, and Preservation, American Chem‐
ical Society, Washington, 1990, p. 407, Chapter DOI:
10.1021/ba‐1990‐0225.ch015, URL
[6] T. Nishiura and S. Imazu, “Experimental study
on the dimensional change of highly degraded wa‐
terlogged wood according to ambient humidity after
preservation treatment”, in P. Hoffmann (ed.), Pro‐
ceedings of the 4th ICOM Group on Wet Archaeological
Materials Conference, Bremerhaven, 1990, ICOM,
Bremerhaven, 1991, p. 117
[7] D. W. Grattan, “A Practical Comparative Study of
Treatments for Waterlogged Wood. Part II: The Effect
of Humidity on Treated Wood”, in D. W. Grattan (ed.),
Proceedings of the ICOM Waterlogged Wood Working
Group Conference, 15‐18th September, 1981, Cana‐
dian Conservation Institute, Ottawa, ICOM Com‐
mittee for Conservation, Waterlogged Wood Work‐
ing Group, 1982, p. 250
[8] M. Sandström, Y. Fors, and I. Persson, "The Vasa's
New Battle. Sulphur, Acid and Iron", Vasa Studies 19,
The Vasa Museum, Stockholm, 2003, p. 21
[9] D. Camuffo, R. Van Grieken, H.‐J. Busse, G.
Sturaro, A. Valentino, A. Bernardi, N. Blades, D.
Shooter, K. Gysels, F. Deutsch, M. Wieser, O. Kim
and U. Ulrych, “Environmental monitoring in four
European museums”, Atmospheric Environment 35,
Supplement No. 1, 2001, doi:10.1016/S1352‐2310
(01)00088‐7 URL , also available at URL [pdf]
[10] M. Cassar, Environmental Management: guide‐
lines for museums and galleries, Museums & Galleries
Commission with Routledge, London, 1995
[11] B. Garrod and A. Fyall, “Managing Heritage
Tourism”, Annals of Tourism Research 27(3), 2000,
pp. 682‐708, doi: 10.1016/S0160‐7383(99)00094‐8,
URL
[12] M. Drdácky, T. Drdácky, D. Creighton, “Impact
of Cultural Tourism upon the Diversity of Built Her‐
itage”, position paper of the PICTURE project Pro‐
active management of the Impact of Cultural Tourism
upon Urban Resources and Economies, 2007, avail‐
able at URL [pdf] (accessed November 2010)
[13] D. Camuffo, G. Sturaro, and A. Valentino,
“Showcases: a really effective mean for protecting
artworks?”, Thermochimica Acta 365(1‐2), 2000,
pp. 65‐77, doi:10.1016/S0040‐6031(00)00614‐6,
URL
[14] M. Cassar, P. Brimblecombe, T. Nixon, C. Price,
C. Sabbioni, C. Saiz Jimenez, and K. Van Balen,
Technological requirements for solutions in the con‐
PREVENTIVE CONSERVATION OF ARCHAEOLOGICAL WOOD
servation and protection of historic monuments and
archaeological remains, European Parliament, Kirch‐
berg, Luxembourg, 2001, p. 43, available at URL
[pdf] (accessed July 2010)
[15] A. Young and M. Cassar, “Indoor Climate and
Tourism Effects ‐ a UK perspective”, in M. Drdácký
(ed.), European Research on Cultural Heritage, State‐
of‐the‐Art Studies, Vol. 2, ITAM 2004, Academy of
Sciences of the Czech Republic, Prague, 2004, pp.
405‐412, available at URL [pdf] (accessed August
2010)
[16] E. Hocker, “Maintaining a Stable Environment:
Vasa´s New Climate‐ Control System”, Journal of
Preservation Technology 41(2‐3), 2010, available at
URL [pdf] (accessed August 2010)
[17] B. Håfords, The climate of the Vasa Museum –
problems in coordinating the museum object and
the museum climate, 1997, available at URL (ac‐
cessed July 2010)
[18] I. Hall Roth and L. Malmberg, “Save the Vasa‐
An Introduction”, in P. Hoffmann, J. A. Spriggs, K.
Strætkvern and D. Gregory (eds.) Proceedings of
the 9th ICOM Group on Wet Archaeological Materials
Conference, Bremerhaven, 2005, ICOM, 2005
[19] E. Hocker, L. Dal, and F. Hocker, “Understand‐
ing Vasa’s Salt Problem: Documenting the Distribu‐
tion of Salt Precipitations on the Swedish Warship
Vasa”, in Proceedings of the 10th ICOM Group on Wet
Organic Archaeological Materials Conference, Bremer‐
haven, 2008: ICOM/RACM, Amersfoort, 2009, p. 479
[20] M.N. Mortensen, H. Egsgaard, S. Hvilsted, Y.
Shashoua and J. Glastrup, “Characterisation of the
polyethylene glycol impregnation of the Swedish
warship Vasa and one of the Danish Skuldelev Viking
ships”, Journal of Archaeological Science 34(8),
2007, p. 1217, doi:10.1016/j.jas.2006.10.012, URL
CRISTINA CABELLO‐BRIONESConservator
Cristina Cabello‐Briones is a recent postgraduate
in Preventive Conservation at Northumbria Uni‐
versity (Newcastle, UK). Her dissertation, assessed
with distinction, was about Preventive Conserva‐
tion of Wooden Wreck‐Hulls Retrieved from Un‐
derwater Maritime Environments. She is a first
class graduate in the Conservation and Restora‐
tion of Cultural Heritage from the Escuela Superi‐
or de Conservación y Restauración de Bienes Cul‐
turales de Madrid (Spain), speciality in paintings,
where she studied between 2002 and 2005. In
2008, she completed her second first class BA
degree in the History of Art at the Universidad
Autónoma de Madrid (Spain). Her dissertation
was about Historic Restorations of the Roma‐
nesque Mural Paintings at the National Museum
in Catalonia.
She has recently been awarded with La Caixa Schol‐
arship to study a PhD in Conservation in the United
Kingdom commencing in 2011.
Her most recent projects include the research of
the improvements to the Tate Gallery’s transit
frame wrapping system in order to save on ma‐
terials, time and handling of long term collec‐
tion care and the internship at the Reina Sofía
Museum (Madrid, Spain) assessing the risks for
cultural artefacts during mounting of exhibitions.
CRISTINA CABELLO‐BRIONES
52 e‐conservation
[21] Personal communication with Emma Hocker,
July 2010
[22] Y. Fors, Sulfur‐Related Conservation Concerns
for Marine Archaeological Wood. The Origin, Spe‐
cification and Distribution of Accumulated sulfur
with some Remedies for the Vasa, Doctoral Thesis,
Department of Physical, Inorganic and Structural
Chemistry, Stockholm University, 2008, p. 94
Are you reading this?So is everybody else...
econservationline
For advertisingand other information on publicity,
please contact
general@e‐conservationline.com
and request a copy of our mediakit.
THE USE OF GROUND PENETRATING RADARFOR THE ASSESSMENT
OF THE CONSERVATION STATEOF AN HISTORIC BUILDING
THE USE OF GROUND PENETRATING RADARFOR THE ASSESSMENT
OF THE CONSERVATION STATEOF AN HISTORIC BUILDING
By Lucian Cristian Ratoiu
This article proposes the elaboration of a dedicated database for monitoring the evolution of buried
structures or anomalies of the underground layers based on data collection after periodic surveys. The
use of a radar technique in establishing an efficient assessment protocol of the conservation condition
of historical building foundations proves to be a useful and accessible task due to its major advantages.
This non‐destructive technique with fast and accurate acquisition time meets the characteristic require‐
ments for the analysis of historic monuments. The possibility to perform periodic analyses allows the
monitorization required for long‐term preservation of cultural heritage. A case study is presented with a
survey of the foundation of an historic building, dating from the beginning of the 20th century and located
in the “Dimitrie Gusti” National Village Museum from Bucharest, Romania.
Research aims
The research comprises two main objectives: to
establish a useful and efficient instrument for
periodic monitoring and evaluation of the con‐
servation state or rehabilitation interventions on
historic monuments; and to elaborate a dedicated
system for data management that can provide
important information for long time preserva‐
tion of cultural heritage.
Introduction
Ground Penetrating Radar (GPR) is a well‐known
technique applied to identify buried structures,
cavities or anomalies below the ground surface
with the advantage to estimate the depth at which
they can be found. The technique is based on the
emission‐reception of electromagnetic pulses and
on their propagation in the soil.
The different scanning results are strongly de‐
pendent on the type of material encountered
which is characterized by the dielectric constants.
The radargrams resolution depends on factors
such as the central antennas frequency, sampling
frequency, antennas separation, and speed of
acquisition, among others. The environmental
responses, characterized through the resolution
and depth of the wave propagation are dependent
on the electromagnetic properties of the under‐
ground medium, the soil water concentration, the
electric conductivity or the presence of metals.
A fast survey by nondestructive means allows to
establish an efficient plan for periodic control of
historic building foundations. The aim of this re‐
search is to gather a particular database designed
Figure 1 and 2. The GPR system in Ruşeţu household – 2008(upper) and 2009 (lower).
e‐conservation 55
ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING BY GPR
to compare the results and to detect changes in
an early stage.
Regular monitoring ensures a constant determi‐
nation of minor changes in the historic monuments
foundations. Preventive interventions ensure a
long term preservation, thus avoiding major de‐
gradations such as cracks or internal displacements
of the walls structure.
Case Study
The Ruşeţu house, dating from the early 20th cen‐
tury, is a typical Romanian house that was trans‐
ported and reconstructed in the “Dimitrie Gusti”
National Village Museum, an open‐air ethno‐
graphic museum in Bucharest that houses tradi‐
tional Romanian architecture. The household con‐
sists of the dwelling house and some annexes to
shelter animals.
The house was built from common clay mixed with
vegetal aggregates, and the walls were painted
with lime. The facade and one side of the house
are provided with a low porch, supported on un‐
decorated wood poles, with a traditional roof
made by several layers of small pieces of wood.
On the back of the house, the roof also covers
the annexes.
The conservation problems were mainly caused
by capillarity moisture, especially on the annex
rooms, combined with the frailty of the specific
constituent materials.
Data Acquisition
The first acquisition campaign was made in 2008,
before the rehabilitation of the building. The ob‐
jective was to study the conservation state and to
record the possible anomalies of the underground.
Figure 3. Ruşeţu house in 2008, before rehabilitation.
56 e‐conservation
LUCIAN CRISTIAN RATOIU
In 2009, a second acquisition campaign was per‐
formed after the rehabilitation works, with the
objective of highlighting the differences before
and after the interventions.
For the data acquisition, two types of antennas
were used, with frequency at 500 MHz and 800
MHz. The use of two different antennas allowed
to investigate at higher depths with a higher res‐
olution at subsurface layers, and also to confirm
the recorded data. A very important factor is to
verify the environmental conditions, once the
high humidity of the soil caused by rain can influ‐
ence the measurements. Fundamental in obtain‐
ing accurate data is to adjust the system acqui‐
sition parameters to the analyze requirements.
Two parameters are essential. One is the samplingfrequency that has to be 10 times the center fre‐
quency of antenna in use. Second is the time win‐dow/number of samples which must be chosen
properly: to long window burdens the system un‐
necessarily and too short may ruin the data. Only
by keeping the same parameters used previously a
precise comparison of the results can be ensured.
An effective procedure for fast control on the re‐habilitation of historic monuments foundations
For the development of an efficient work guide used
in examination of cultural heritage, the strictness
Figure 4. Ruşeţu house in 2009, after rehabilitation.
Figure 5.The plan of the Ruşeţu houseand the scanning directions.
e‐conservation 57
ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING BY GPR
of interventions and investigations allowed by the
legislation should be considered as prior.
From this point of view, priority should be given
to non‐destructive and non‐invasive techniques
that provide high accuracy data that do not affect
the object.
Specific GPR information gathered requires an
organized and dedicated database that can allow
to compare and to follow the evolution of the con‐
servation state. In this case actions can be taken
at an early stage of decay, allowing to put in prac‐
tice preventive conservation measures.
Likewise, using the GPR technique with the aim of
evaluating the rehabilitation of building found‐
ations will prove to be an easy task, thanks to the
major advantages, characteristic for this fast and
non‐invasive method.
Using a comparative model for observing the ob‐
tained results will indicate modifications specific
for the time elapsed since the last data acquisition.
Figure 6 (below). Data acquisition from the 2008 campaign.
Figure 7. Data acquisition from the 2009 campaign.
58 e‐conservation
LUCIAN CRISTIAN RATOIU
The frequency of the acquisitions number will allow
a more accurate behavior of the ground founda‐
tions, which is mainly influenced by the compacta‐
tion movements of the soil layers caused by the
high percentage of capillary moisture or by the
new interventions carried out in that area.
The steps of the procedure must include: strict
delimitation of the area, description of the work
conditions, recording the data in the same envi‐
ronmental conditions, identical processing of the
data collected, resuming to new acquisitions after
a well established time, using the same settings
for the GPR system, and using at least two differ‐
ent frequency antennas to confirm the results
obtained.
Data Processing and Interpretation
Once collected, the data was processed using
routine corrections, provided by the dedicated
software – the post processing medium of GPR
data collected, to ensure a better visualization
of the results.
The radargrams allow to emphasize the layer anom‐
alies or eventual objects buried and to point out
their Cartesian coordinates. The runtime was kept to
ensure the same data post‐processing, the eventu‐
ally changing being the result of foundation evolu‐
tion, instead of data workflow differences.
On the radargrams recorded in the same years the
anomalies that correspond to the Cartesian co‐
ordinates are emphasized, which demonstrates
Figure 8. Procedure diagram.
Figure 9. Segment G‐H, 500 MHz antenna, 2008‐2009. Figure 10. Segment G‐H, 800 MHz antenna, 2008‐2009.
e‐conservation 59
ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING BY GPR
Figure 11. Segment A‐B, 500 MHz antenna, 2008.
Figure 12. Segment A‐B, 500 MHz antenna, 2009.
LUCIAN CRISTIAN RATOIU
60 e‐conservation
Figure 13. Segment A‐B, 800 MHz antenna, 2008.
Figure 14. Segment A‐B, 800 MHz antenna, 2009.
ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING BY GPR
e‐conservation 61
Bibliography
[1] L. B. Conyers and D. Goodman, Ground Penet‐
rating Radar: an Introduction for Archaeologists,
AltaMira Press, Walnut Creek, London and New
Delhi, 1997
[2] D. J. Daniels (ed.), Ground Penetrating Radar,
The Institution of Engineering and Technology,
London, 2007
[3] F. García García, M. Ramírez Blanco, I.l Rodríguez
Abad, R. Martínez Sala, I. Tort Ausina, J. Benlloch
Marco, and J. L. Montalvá Conesa, “GPR technique
as a tool for cultural heritage restoration: San Miguel
de los Reyes Hieronymite Monastery, 16th century
(Valencia, Spain)”, Journal of Cultural Heritage, Vol‐
ume 8 (1), 2007, pp. 87‐92, doi:10.1016/j.culher.
2006.10.005, URL
[4] V. Pérez‐Gracia, F. García, L. G. Pujades, R. Gon‐
zález Drigo, and D. Di Capua, “GPR survey to study
the restoration of a Roman monument”, Journal of
Cultural Heritage, Volume 9 (1), 2008, pp. 89‐96,
the validity of the measurements. The differences
between the 2008 and 2009 results are obvious.
At the depth of about 1–1,4 m are highlighted
the reflections of the electromagnetic radiation
received from the intervention over the founda‐
tion with concrete. This intervention was made to
consolidate the porch and the wall façade corres‐
ponding to the main entrance.
Even if the scanned area does not correspond pre‐
cisely to the place where the intervention was
made, the reflections are present because the
electromagnetic radiation is propagated in the
soil under the form of a truncated cone. That ex‐
plains why those reflections are present in 2009
– otherwise under the strict area of the house,
delimited by exterior walls, the interventions
concerned just a superficial depth.
Conclusions
We have obtained a high accuracy examination by
nondestructive means of the Ruşeţu house foun.‐‐
dation at the Village National Museum “Dimitrie
Guşti” in Bucharest, Romania.
The results highlighted the anomalies of the un‐
derlayers in a mapping format that also provided
the depths at which they could be found.
A fast and efficient acquisition model was applied
using two different frequency antennas (500 and
800 MHz). The information was processed and
collected in a dedicated database elaborated for
long term monitorization.
The differences between the recordings performed
in 2008 and 2009 revealed an existent interven‐
tion. This involved the consolidation of the entire
perimeter of the construction with concrete.
Proofs of this intervention have been identified
by the 2009 scan at a depth ranging between
1 m and 1.4 m. These data were not present in the
2008 research.
Periodic data acquisition obtained according to
the procedure proposed will determine an ac‐
curate characterization and comparison of the
collected results.
Acknowledgements
The author would like to acknowledge the support
of his coordinator Roxana Rădvan and colleague
Dragoş Ene from the National Institute for Deve‐
lopment and Research in Optoelectronics INOE
2000. Also a special thank is addressed to Vivian
Dragomir, from the Village National Museum
“Dimitrie Guşti”, Bucharest.
62 e‐conservation
LUCIAN CRISTIAN RATOIU
doi:10.1016/j.culher.2007.09.003, URL
[5] D. Barilaro, C. Branca, S. Gresta, S. Imposa, A.
Leone, and D. Majolino, “Ground penetrating radar
(G.P.R.) surveys applied to the research of crypts
in San Sebastiano's church in Catania (Sicily)”,
Journal of Cultural Heritage, Volume 8 (1), 2007,
pp. 73‐76, doi:10.1016/j.culher.2006.10.003, URL
[6] S. Castellaro S. Imposa, F. Barone, F. Chiavetta,
S. Gresta, and F. Mulargia “Georadar and passive
seismic survey in the Roman Amphitheatre of Catania
(Sicily)”, Journal of Cultural Heritage, Volume 9(4),
2008, pp. 357‐366, doi:10.1016/j.culher.2008.03.
.004, URL
[7] F. Soldovieri, and L. Orlando, “Novel tomographic
based approach and processing strategies for GPR
measurements using multifrequency antennas”,
Journal of Cultural Heritage, Volume 10, Supple‐
ment 1, ICT and Remote sensing for Cultural Resource
Management and Documentation, 2009, pp. 83‐92,
doi:10.1016/j.culher.2009.09.001, URL
[8] P. X. Neto, and W. E. de Medeiros, “A practical
approach to correct attenuation effects in GPR
data”, Journal of Applied Geophysics, Volume 59
(2), 2006, pp. 140– 151, doi:10.1016/j.jappgeo.
2005.09.002, URL
LUCIAN CRISTIAN RATOIUConservator‐restorer
Contact: [email protected]
Lucian Cristian Ratoiu is a conservator‐restorer
specialized in mural paintings. He graduated in
2007 from the Department for Conservation‐Res‐
toration Works of Art of the National University
of Art in Bucharest, Romania. Since 2008, he is
working as an assistant researcher at the Centre
of Excellence for Restoration by Optoelectrical
Techniques of the National Institute for Develop‐
ment and Research in Optoelectronics INOE.
CALL FOR SUBMISSIONS
e‐conservation magazine is open to submission
of articles on a wide range of relevant topics
for the cultural heritage sector.
Next deadlines for article submission are:
for Issue 19, April 2011 – submissions due
1st March 2011
for Issue 20, June 2011 – submissions due
1st May 2011
Nevertheless, you can always submit your
manuscript when it is ready. Between the
receival of the manuscript until the final
publication may pass up to 3 months
according with:
‐ the number of the manuscripts on hold,
submitted earlier by other authors
‐ the release date of the upcoming issue
‐ the pre‐allocated space in the magazine
to each section
Please check our publication guidelines
for more information.
e‐conservation 63
ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING BY GPR
case
stud
y
Virtual reconstruction of the polychromy was chosen to pre‐
serve the artistic authenticity of the sculptures “Evangelist”
and “Madonna and Child”, producing variants of virtual
chromatic integration that are aimed at creating images in‐
dicative of the original appearance of the objects. Represent‐
ations of this type come as a manifestation of a mental
exercise to view complete polychrome sculptures, or their ap‐
pearance after chromatic integration, with the advantage that
there is no direct intervention on the objects. Virtual restora‐
tion of the polychromy can be achieved in several ways, de‐
pending on options such as image editing technical skills
and available software.
VIRTUAL AESTHETIC PRESENTATIONOF POLYCHROME SCULPTURES
By Daniela Cristina Pintilie
Preserving the artistic authenticityof polychrome carved wood piecesin the conservation‐restoration process
Figures 1 and 2.“Evangelist” polychrome sculpture.
e‐conservation
Introduction
Each work of art, regardless of its execution tech‐
nique, dating or conservation state, requires a
thorough analysis prior to any intervention. It is
absolutely necessary to know the historical con‐
text of objects in the restoration process and the
possibility to compare them with similar objects
when they are in advanced state of decay, in order
to avoid a hypothetical undesirable restoration and
its consequences. Every possible intervention must
be treated critically to preserve the artistic authen‐
ticity of the object, being very important to avoid
any operations that are not necessarily required.
In this article two case studies are on display, two
conservation‐restoration proposals that include
chromatic integration and polychromy virtual re‐
construction. The reconstructions made using
software are not aimed at creating models of the
objects, or their possible aspects after interven‐
tion, but are intended to achieve virtual images
of the undamaged sculptures. Until recently, but
even today, polychromy reconstruction has been
performed directly on objects, either by repainting
–intervention that has affected the authenticity
of the sculptures, or by the complete reproduction
of the object, operation that is similar to the vir‐
tual reconstruction.
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
65
Figures 3 and 4. Stratigraphy at the level of the garment:a. support of wood; b. original primer; c. green; d. blue;e. repainting primer; f. green – repainting.
66 e‐conservation
I. Case Study:“Evangelist” Polychrome Sculpture
The Evangelist sculpture has been dated back to
the early eighteenth century, having Transylvania
as its place of origin. Today it belongs to a private
collection. It has 63 cm height, 24 cm width and
a thickness varying between 3.3 and 12.5 cm. It
was executed in weak tempera on carved wooden
support. The sculpture is a bas‐relief that was part
of an overall frieze type, probably from a shrine.
In time, the sculpture has been subjected to some
interventions at the level of the paint layer, mainly
repaintings that are visible in the area of the green
garment. Different layers could be identified as:
green whitened with primer, blue whitened with
primer and a final layer of green. Given that the
layers of repainting are powdery and the original
is not, it is supposed that for their execution in‐
compatible materials were used or the binder was
applied in insufficient concentration.
Preserving the artistic authenticity of sculpture
For the virtual reconstruction of the Evangelist
polychrome sculpture photographs acquired by
optical microscopy were used, of samples taken
from areas where the painting was preserved.
Virtual restoration of the polychromy of theEvangelist sculpture
L*a*b* parameters of the pigments were deter‐
mined using Adobe Photoshop, using photos
taken from optical microscope Leica DMLS from
the laboratory of Chemistry of the Conservation
and Restoration Department of the National Art
University, Bucharest. For each color five meas‐
urements from different points were recorded in
order to obtain values as close as possible to the
reality.
Figure 5. Map of the sampling areas.
CRISTINA‐DANIELA PINTILIE
e‐conservation 67
The average of the parameters obtained from the
five points was calculated and used as standard
for the subsequent mathematical calculations to
determine the ∆E* (total difference), made in
Microsoft Excel®. (∆E *= √ (∆ L* a* 2 + ∆ 2 + ∆ b*
20). Once determined, values greater than 10 ∆E*
were excluded and the average was recalculated
resulting in the determination of the local color
parameters. The same calculations were repeated
for each color.
L* represents brightness, a* chromatic parameters
on the Magenta – Green axis, b* chromatic para‐
meters on the Yellow‐Blue axis, C* chromatic in‐
dex,∆C* total color difference, H* is the hue angle,
∆H* hue angle range. ∆* values indicate how much
the L*a*b* parameters differ from the standard
and the analyzed values. The objective is to obtain
a color space for classifying numerical differences.
A* and b* parameters are independent of the
brightness L*, expressing only color differences,
namely: if a* is greater, it means that the sample
has more red than the standard, or more green if
a* is lower; a greater b* value shows that the sam‐
ple is more yellow, or more blue for a lower b*
value; and finally when L* is greater, the sample
is lighter than the standard, and darker for a lower
L* value.
Starting with the garment stratigraphy, where the
sequence of the layers it is best revealed, three
possible aspects of the object at a certain point
during time were virtually generated with Adobe
Photoshop. Thus, an image of the complete poly‐
chromy of the object was obtained without inter‐
fering with it. After the calculations, the results
were illustrated through graphic representations.
Determination of the L*a*b* values for red
(garment)
The points in which the L*a*b* parameters were
recorded on the optical microscopy photography
were marked with R (R1, R2, R3, R4, R5). For R2
and R3, ∆E* is greater than 10, therefore, the
corresponding L*a* b* values were excluded and
the average was recalculated from the remaining
values (figure 6).
Determination of the L*a*b* values for ocher
The points in which the L*a*b* parameters were
recorded were marked with C (C1, C2, C3, C4, C5).
To achieve the final average, i.e., to establish the
L*a* b* parameters of the carnation, measure‐
ments from points C1 and C5 with ∆E* greater
than 10 were eliminated (figure 7).
Figure 6. Determination of the L*a*b* values for red (garment). Figure 7. Determination of the L*a*b* values for ocher.
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
68 e‐conservation
Determination of the L*a*b* values for gray (book)
The points in which the L*a*b* parameters were
recorded were marked with G (G1, G2, G3, G4, G5).
All measureºments have ∆E* value within the ac‐
cepted parameters, so all were used to calculate
the final average (figure 8).
Determination of the L*a*b* values for whitened
green
The points in which the L*a*b* parameters were
recorded were marked with VA (VA1, VA2, VA3, VA4,
VA5). ∆E* value for VA1 was greater than the limit
so it was eliminated (figure 9).
Determination of the L*a*b* values for blue
The points in which the L*a*b* parameters were
recorded were marked with A. ∆E values greater
for the L*a*b* parameters of the points A2, A4
and A5, so the final average was recalculated us‐
ing the remaining ones (figure 10).
Determination of the L*a*b* values for green
(garment)
The points in which the L*a*b* parameters were
recorded were marked with V (V1, V2, V3, V4, V5).
Having a value greater than 10, the point V3 was
removed in order to achieve the average of the para‐
meters L*a*b* corresponding to green (figure 11).
Given the garment stratigraphy and the L*a*b*
values obtained we were able to achieve three
possible aspects that the object might have had
during the past. The layers of repaintings are well
distinguished, as follows: whitened green, azur‐
ite blue, green.
Figures 8‐11 (from up to down).Determination of the L*a*b* values for gray (book);
whitened green; blue; and green (garment).
e‐conservatione‐conservation
CRISTINA‐DANIELA PINTILIE
From up to down,left to right:
Figure 12. Evangelistsculpture after virtual,partial polychromy res‐toration.
Figure 13. EvangelistSculpture after virtualpolychromy restoration ‐whitened green.
Figure 14. EvangelistSculpture after virtualpolychromy restoration– blue.
Figure 15. EvangelistSculpture after virtualpolychromy restoration– green.
e‐conservation 69
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
70 e‐conservation
Virtual chromatic integration of the Evangelistsculpture
In order to preserve the artistic authenticity of the
object without interfering with it, two possible
aspects were obtained after chromatic integration
carried out in velatura technique only on the ori‐
ginal, visible ground layer.
This operation allows the artistic authenticity to
be preserved by minimal intervention on the ob‐
ject, placing instead more emphasis on its con‐
servation.
As with the virtual reconstructions of the poly‐
chromy, digital chromatic integration does not
intend to achieve variants from which to choose
the most appropriate, but only to satisfy the de‐
sire to visualize the outcome of an intervention
of this type.
Archaeological restoration is justified by the fact
that the polychromy is preserved only in a very
small percentage, from which a certain propor‐
tion is repainting.
Chromatic integration trials made directly on the
object are not 100% reversible, affecting the ori‐
ginal to some extent. Removal of tests inevitably
damages part of the original matter, either the pla‐
ster or the paint layer, affecting thus the authen‐
ticity of the object. The risk of damaging the sculp‐
ture through interventions that are not necessarily
required is very high and is not justified, especially
since its conservation does not depend on them.
Although the proposed treatment is based on an
archaeological approach, two versions of virtual
chromatic integration have been achieved with
an image editing software in order to emphasize
that this operation is not absolutely necessary.
Figures 16‐18. Left: original aspect of the Evangelist sculpture; Center: a first variant of virtual chromatic integration;Right: a second variant of virtual chromatic integration.
CRISTINA‐DANIELA PINTILIE
Figure 19. Polychrome sculpture Madonna and Child.
e‐conservation 71
II. Case Study:Madonna and Child Polychrome Sculpture
The sculpture Madonna and Child dates from the
twentieth century and is also originally from Tran‐
sylvania. Today it belongs to a private collection.
It was executed in tempera on carbonized wood
support, which is visible at the naked eye inside
the lacunas of the pictorial layer. No repaintings
were identified on this sculpture.
Conservation state
The wood was carbonized before the execution of
the polychromy, which leads to the assumption
that the sculpture is a fake and that the support
was burned so that the polychromy deteriorates
in a short time. The carbonized surface transpires
through the preparation and color layers, creating
the impression of an antique.
The assessment of the conservation state at the
level of the wood support shows carbonizations,
lacunas on large areas and surface deposits. The
pictorial layer is friable and has a poor adherence
to the substrate, showing erosions, lacunas, de‐
posits and stains.
Figure 21. Madonna image: a ‐ stains due to carbonized woodsupport; b ‐ erosion of color layer; c – lacunas of the color lay‐er up to the preparation layer; d – lacunas of the preparationlayer up to the wood support.
Figure 20. Stratigraphy in the garment: a ‐ wood support;b ‐ carbonized wood support; c – preparation layer; d ‐ firstcolor layer ‐ red; e ‐ second color layer ‐ blue.
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
72 e‐conservatione‐conservation
Preserving the artistic authenticity of thepolychrome sculpture Madonna and Child
When dealing with a fake, the issue of authenti‐
city is different to some degree. On the one hand,
there is the issue of preserving the authenticity
of a work normally done in tempera on wood tech‐
nique, and on the other hand, preserving the au‐
thenticity as it was thought by its author, through
the carbonization of the wood and the creation
of a false patina. Given these circumstances, the
fairest solution to the object and to the author's
intention is to adopt an archaeological approach
to its restoration.
Operations performed directly on the object
From the methodological point of view a resto‐
ration that includes minimal interventions was
chosen. Light surface deposits were removed
with a soft brush, after which the pictorial layer
was consolidated in several stages with fish glue
in different concentrations. The deposits present
on the painted surface, on the preparation layer
and on the wood visible inside the gaps were re‐
moved.
Virtual restoration of the polychromy of theMadonna with Child sculpture
The sculpture benefited from its integrity for a very
short period of time. There is also the possibility
that some gaps were induced deliberately by the
author. To get a picture of the sculpture as it could
have looked in the beginning, a polychromy vir‐
tual restoration was carried out.
Unlike in the case of the Evangelist sculpture, to
reconstitute the polychromy of this object several
particular issues must be taken into account, due
to its specific execution technique. The red color
and the carbonized wood surface that became
visible through the blue create the false antique
impression by darker or lighter areas. This gives
personality and authenticity to the sculpture.
Thus, we chose to restore the polychromy by mim‐
icking the existing areas using an image editing
software like Adobe® Photoshop®, method that
allowed us to keep the artificial antique effects.
Figure 22. Madonna and Child sculpture after virtual, partialpolychromy restoration.
CRISTINA‐DANIELA PINTILIE
e‐conservation 73
Figure 23. Madonna and Child sculpture after virtualpolychromy restoration.
e‐conservation
The virtual restoration of the polychromy is not
aimed at creating a model, or a sketch of what the
object could become if subject to possible inter‐
ventions, but stands for projecting a mental re‐
construction of what the sculpture would have
been immediately after its creation.
Virtual chromatic integration of the Madonnaand Child sculpture
Chromatic integration was carried out virtually by
applying a neutral glaze on the visible preparation
layer with the intention to send the gaps to the
background so that to create a surrounding for
the original existing painting. Given this and the
practical execution with reversible materials, namely
water colors, the restoration principles should be
respected, but one can not predict whether the
outcome will be satisfactory and beneficial for the
object. In this respect, virtual representations
bring a great contribution to the establishment
the methodology for restoration, especially the
treatment of the gaps.
As in the case of the Evangelist sculpture, we do
not aim to achieve chromatic integration versions
in order to select the best from them, but to be
able to visualize this option without interfering
with the authenticity of the object.
Even if we chose an archaeological restoration type,
all possible versions should be considered, since
at a future restoration, in a detrimental context
one might even opt for the repainting of the sculp‐
ture.
By virtual chromatic integration the author's in‐
tent to create an antique‐looking sculpture is re‐
spected and at the same time a coherent reading
of the sculpture is achieved.
Conclusions
The authenticity of the works of art is mainly pro‐
tected by minimal intervention especially during
restoration, but this does not mean that the doc‐
umentation of the object should also be limited.
Whether it is decided to remove or not the re‐
paintings, this aspect must be documented by
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
laboratory analyses, cross‐sections, etc., which
eventually will be part of the file that accompanies
the object and can serve for a future restoration.
Unfortunately, virtual representations are not al‐
ways well received, and their purpose may be mis‐
interpreted. It is true that they can serve as a range
of possible options to a reconstitution, repainting,
restoration or chromatic integration, but their
value in the preservation of artistic authenticity
should not be neglected.
If until recently the only possibilities to materialize
a reconstructed image of a work of art, or of an
architectural ensemble, of which some elements
are missing or have lost polychromy during time,
Figures 24 and 25. Madonna and Child sculpture before and after virtual chromatic integration.
CRISTINA‐DANIELA PINTILIE
74 e‐conservatione‐conservation
DANIELA‐CRISTINA PINTILIEConservator‐restorer
Contact: [email protected]
Daniela‐Cristina Pintilie is a conservator‐restorer
specialised in panel paintings. She graduated in
2008 from the Faculty of Art History and Theory,
Conservation and Restoration section, of the Na‐
tional University of Arts in Bucharest, Romania
where she also completed a Master degree in 2010.
During her training, she participated in different
conservation projects such as of the wooden Church
of the Nativity of the Virgin from Ieud, Maramures,
the Romanian Athenaeum, and the churches Colţea, Stavropoleos and Doamnei in Bucharest, the
Beheading of St. John the Baptist from Arbore, and
St. Nicholas from Bălineşti. She currently works
for a private conservation company in Bucharest.
were repaintings or reproductions, now we can
perform virtual representations, which not only
do not affect in any way the original, but are more
accurate, involve lower costs, require fewer con‐
sumption of materials, and the diversity of treat‐
ment of various aspects is greater.
Polychromy virtual restoration can be achieved
in several ways, where possible, as could be ob‐
served in this study. It can be precise, as in the
case of the Evangelist sculpture, for which values
L*a*b* were determined, or intuitive as in the
case of the Madonna and Child sculpture. Both
versions are useful, and during the course of an
intervention the second may be preceded by the
first one. Such representations can protect works
of art from operations that might compromise
their authenticity and integrity. No operation
performed directly on the object, be it cleaning
tests or chromatic integration proposals, is fully
reversible.
To preserve the artistic authenticity of an object
every intervention must be treated critically, and
it is very important to avoid any operations that
are not necessarily required.
Note
The present article is an extract from author’s
dissertation work with a major specialization ‐
artistic heritage conservation and restoration
methodologies: "Protecting the artistic authen‐
ticity of polychrome carved wood pieces in the
process of conservation and restoration", carried
out within the Department of Conservation and
Restoration, National University of Arts – Bucha‐
rest. The author graduated in June 2010 under
the coordination of Lect. univ. Dana LuminiţaPostolache – conservator‐restorer, Lect. univ.
Olimpia Hinamatsuri Barbu and Prof. univ. Ioana
Gomoiu, conservation‐scientists.
Selected bibliography
[1] C. Brandi, Theory of restoration, Istituto Centraleper il Restauro/Nardini Editore, 2005
[2] O. Cassaza, Il restauro pittorico‐ nell'unita di meto‐dologia, Nardini editore, 2007
[3] R. Peral, D. Sagasti and S. Sillaurren, "Virtual Re‐storation of Cultural Heritage Through Real‐Time 3DModels Projection", in M. Mudge, N. Ryan, and R. Sco‐pigno (eds.), VAST 2005, The 6th International Sym‐posium on Virtual Reality, Archaeology and CulturalHeritage, Oct 30‐Nov 4, 2006, Pisa, Italy, URL [pdf]
[4] F. Descamps, and J. Carballo (eds), Methodology forthe Conservation of Polychromed Wooden Altarpieces,Junta de Andalucía, Consejería de Cultura and the J. PaulGetty Trust, 2006, URL [pdf]
[5] G. López, M. José, and F. Descamps (eds.), Workshopon Methodology for the Conservation of PolychromedWooden Altarpieces: Document on Retablos 2002, TheGetty Conservation Institute and Junta Andalucía Con‐sejería de Cultura, 2004, URL [pdf]
VIRTUAL AESTHETIC PRESENTATION OF POLYCHROME SCULPTURES
e‐conservation 75e‐conservation
e‐conservation magazine offers the possibility to publish bilingual articles in the html version. Articles inEnglish may also be published in French, Spanish, Portuguese, Italian and Romanian, at authors request.
No. 18, February 2011
ISSN: 1646‐9283
Registration Number125248
Entidade Reguladorapara a Comunicação Social
Propertye‐conservationline, Teodora Poiata
PeriodicityBimonthly
CoverDetail of the Vasa warship, the Vasa Museum, Stockholm.
Photo by Karolina Kristensson,The Swedish National Maritime Museums
Executive EditorRui Bordalo
EditorsTeodora Poiata, Anca Nicolaescu
CollaboratorsAna Bidarra
Daniel Cull
Graphic Design and PhotographyAnca Poiata, Radu Matase
ExecutionTeodora Poiata
AddressRua de Santa Catarina, nº 467, 4D
4480‐779 Vila do Conde, Portugal
www.e‐conservationline.com
All correspondence to:general@e‐conservationline.com
LICENCE
Attribution‐Noncommercial‐No Derivative Works 2.5Portugal
You are free:to Share — to copy, distribute and transmit this work
Under the following conditions:
Attribution. You must attribute the work in the manner specifiedby our licence, best by linking to CC website.
Noncommercial. You may not use this work for commercialpurposes.
No Derivative Works. You may not alter, transform, or buildupon this work.
e‐conservationline informs that the published information isbelieved to be true and accurate but can not accept any legalresponsibility for any errors or omissions that may occur ormake any warranty for the published material, which is solelythe responsability of their authors.
77e‐conservation
econservation magazine is published and distributed under theCreative Commons LicenceAttribution Noncommercial No Derivative Works.