Transcript
WelcomeMy name is Yong En
Physical structures and surfaces for paintings
Painting surfaces – hardwood plywood
Veneer/Plywood hardwood boardRigid Support
Today, choose those glued using Waterproof acid free adhesives:- PVA (poly vinyl acetate)- EVA (ethylene vinyl acetate)- PU (polyurethane)glues.
Formaldehyde based glues are commonly used, but try to stay away from these (carcinogenic!!!).
Layers are glued at right angles to each other to reduce warping
Painting surfaces – hardwood
Properly treatedMaple, birch, oakTeak etc.
Rigid support
Ideally: seasoned, air dried, quarter sawn
e.g. Mona Lisa -> oil on poplar wood
Painting surfaces – hardboard
Made from wood fibres
Sometimes also called “Masonite” (brand).
Strong board
Ideally non-tempered type (no oil applied to the board during production)
Choose formaldehyde free types
Painting surfaces – DO NOT USE
• Softwood• Particleboard• MDF - Medium Density
Fibreboard • HDF – High Density
Fibreboard
They will swell and/or warp a lot more than hardwood type boards
Painting surfaces - woodImportant things to note:Is the wood low acid?Is it sufficiently seasoned (to reduce moisture content to minimise warping)?
Before painting – all sides and surfaces of the wood have to be sealed with a waterproof coating
-> prevent chemicals in the wood from affecting the paint when they leach out
Painting surfaces – metal and glass
Ian DavenportColorfall: Cobalt, Vermillion, Cobalt, 2013acrylic on stainless steel mounted on aluminum panel
Surface typically roughened for better adherence of paints.
Artists use it because of their smoothness.
Typically stainless steel, aluminium or copper are used. Must take note of any possible chemical reactions though
Painting surface – paperNot suitable for oils -> cause paper to deteriorate quickly.Used more often for acrylic, watercolour, dry mediums, ink painting.
Main component: alpha cellulose (plant fibres)1. 100% Cotton rag – flexible and long
fibres2. 100% Linen rag – from flax plant,
stronger but less flexible than cotton3. Wood pulp / woodfree / wood sulfite–
most common kind, extracted from wood chips, leaves residual lignin
4. Rag paper – tricky labelling: might be even as little as 20% cotton cellulose
Cellulose fibres
LigninPlant’s ‘glue’ in their cell walls
in paper (wood pulp paper):Becomes acidic and turns yellow/brown over timecotton and linen cellulose are lignin free)
in wood boards:Leaches out and causes structure of wood to break down, and increases acidity which might damage paint
OBAs“Super high whiteness”Normally, cellulose has a natural off white colour.So, manufacturers add Optical Brightening Agents (OBAs)
Absorb UV range EM waves -> re-emit at blue visible light range -> increase “brightness” (fluorescent effect)
BUT. They break down over time -> cause patchy yellowing and increased acidity
“Archival” paper: tricky labels
1. “100% Cotton rag”, “100% Linen rag” -> ok
2. “Acid Free” ->100% Cotton rag, 100% Linen rag– No bleaching, no rosim or alum for sizing
3. “Buffered” - additional base added to cause paper to have alkaline pH. Good in addition to Acid free.
4. “OBA free / No OBAs” – No Optical Brightening Agents -> good.
5. “pH neutral” -> wood pulp papers that undergo chemical pulping to break down lignin, then pH neutralised by adding a base (e.g. calcium carbonate)
6. “Rag paper” – tricky labelling: might be even as little as 20% cotton cellulose. Try to avoid.
7. “alpha cellulose” – tricky labelling: usually woodfree paper, might have high cellulose content at times. Try to avoid.
Chinese Xuan Paper
Wingceltis tree – fibre from the trunk青檀树 Rice Straw – 1 year natural bleaching process:Cooked in soda ash (sodium carbonate), And bleached for months in sunlight
Japanese Washi Paper • Mulberry (Kozo)• Bamboo• Hemp• Mitsumata• Gampi
Gampi
Chinese/Jap papersKey properties:
Very thin, pretty strong, very smooth, resistance to creases, suitable for calligraphy and chinese ink painting.
Silk
From silkworm cocoonVery smooth withsatin lustre
Used in chinese ink paintings
Yellows over time
Canvas1. Cotton Duck (dutch: ‘doek’ – linen canvas)
So ‘cotton doek’ differentiates itself from ’doek’
Flexible, but does become brittle over time, esp in acidic pollutantsWas never used as painting support before 19th century
Canvas2. Linen (from flax)
Strong and resists rotting, draws less moisture from air, compared to other fibres -> less warping
Retting (controlled rotting of plant stalk, to detach fibres from woody core) -> braking (smash up the central woody core) -> scotching (sep long and short fibres, remove wood) -> spinning/weaving
Canvas3. Hemp (much like linen) - Cannabis Sativa plant
Van Gogh and Rembrandt used hemp
Strong and resists rotting, draws less moisture from air, compared to other fibres -> less warping
Canvas4. Synthetic fibres? – polyester (polyethylene terephthalate (PET))?
Not affected by moisture (doesn’t expand or shrink)
Stretcher
Full mitered bridle joint with keys
A common type:Beveled to 45degrees
Mortise (groove) and tenon (tongue)
*there are many more kinds of joints used,it’s all about woodworking techniques(http://www.conservation-wiki.com/wiki/PSG_Stretchers_and_Strainers_-_III._Materials_and_Equipment)
Stretcher keys
Slot in to tighten the stretcher (where necessary)
Cross bars
Simple Lap Joint-groove cut out in the middleof both wooden bars(not the strongestof joints)
Sizing and Priming
Sizing – for oil paintsCoating the substrate (paper/canvas) with a substance (usually to make it impermeable)Traditionally: Rabbit Skin GlueBut – it is hygroscopic – can absorb water after drying -> (what’s the danger?)
Sizing – for oil paintsToday: recommended use – Acrylic polymer emulsions (e.g. PVA, but many chemical makeups are kind of industrial secrets)
Main purpose: prevent the paints from coming into contact with the substrate (canvas / wood) -> why?
Sizing – in paper productionYes, sizing is also done to commercial paper, via • surface coatings -> coated paper, or
– E.g. Most printer papers to reduce ink being absorbed into paper
– Many different type of coatings are used (industrial secrets)
• mixed into pulp during processing– E.g. making Shu Xuan Paper that is less absorbent
to water (alum added)
Priming (preparing the ground)
Gesso – previously, a combination of chalk or gypsum, animal glue and (white) pigment. Not recommended for use today.
Acrylic emulsion gesso – today, it’s some kind of acrylic resin, with marble dust or silica added (for tooth/grip), and also titanium whiteDries to a tough, flexible film -> don’t use the too flexible ones for large oil paintings -> why?
Priming (for oil paintings)1. Acrylic emulsion gessoes – more rigid kind
2. Oil based grounds: titanium white with safflower oil (applied over the size)
3. Alkyd resin based grounds: titanium white with alkyd resin (applied over size), preferred over oils as alkyds resist yellowing quite well
Such grounds are stiffer to reduce movement in future
Brushes – ‘ang moh’ type
With a few kinds of animals
Thin Paints : Kolinsky / Red Sable (real ones)Has long tapered point and thick belly, soft but with very excellent spring.Has micro-scales -> hold large amount of water Reliable brands: colorpro, escoda, raphael
* today, the word ‘kolinsky’ has been abused by manufacturers with lots of mis-labellingand, kolinsky is not sable
Marten -> Sable hair
Kolinsky (Siberian Mountain Weasel)
Washes, some signwriting:Squirrel HairVery soft and dense, almost no spring, can hold lots of water
Various wash or texture effects: Mongoose HairStiff body, with very soft tips.Holds large amount of water.
*but under various controls now due to illegal trade
Heavier / Thicker paints : Boar/ Hog BristlesThe surface of a hog bristle is flagged, or forked, at the tip. (A Chungking 重庆 hog bristle often has seven to nine flags, making it the best choice for a brush.)
General wash: Ox ear hairFibres are cylindrical -> will not form a fine tip. Strong and springy, suitable for rougher brush techniques
Synthetic brushesA general category for all sorts of synthetic hair -> polyester, polyamide (nylon / taklon) etc. Many innovations today.
Suggested to be used for acrylics
Some good ones can be pretty good.
Round brush: can hold quite a lot of paint, can make bold strokes and thin lines; versatile
Flat brush: can hold medium amount of paint, can make broad strokes or thin lines (using edge)
Filbert brush: Halfway between round and flat, can be used to soften edges
Fan brush: Used to soften / blend, or create rough textures (with more dry paint)
Angle Shader
Bright brush: Shorter than flats, allow for better control in details
Approaches to painting - Glazing
Under-drawingThe drawing before the paint
Under-drawingThe drawing before the paint
Under-paintingWorking out the chiaroscuro: shadows and highlights
Under-paintingWorking out the chiaroscuro: shadows and highlightsUsually black,white + earth tones
Under-paintingWorking out the chiaroscuro: shadows and highlightsUsually black,white + earth tones
GlazingPainting over using transparent colours -> rich depth of colour
Glazing effectsSubtle shifts of colour, e.g. light purple base + yellow (complementart colours)
Glazing effectsSubtle shifts of colour
Chinese / Japanese brushes
Unique structurehold ink in a reservoir (the solid black area inside the brush in the diagram at left) between layers of animal hairs, which are wrapped successively around a long, central core of bristles.
Reservoir hairs: shorter hairs
Inner Core and Outer hairs
Softer hairs: Goat hairs
Reservoir: Space to hold dink
Goat hairSoft hairs that are wavy, coarse, expressive
Tip and sides of brushes, in all positions, are used for painting
Types of marks – chinese ink
人物 – humans工笔 – technical drawing白描 – sketch写意 – expressive水粉 – light colour wash
花鸟– flower and bird工笔 – technical drawing白描 – sketch写意 – expressive没骨 – boneless
山水 – mountain and water没骨山水 – boneless水墨山水 – ink and wash浅绛山水 – light wash青山绿水 / 金碧山水 – green / gold wash
竹石集禽图 元代 王渊 立轴 纸本墨笔
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