Gravure Printing

Gravure PrintingGravure Printing

Cale PolkinghorneCale Polkinghorne

Historical BackgroundHistorical Background

Italian Renaissance 1300’s.Italian Renaissance 1300’s. Engravings and etching into soft copper.Engravings and etching into soft copper. A channel or sunken area is left, this holds the A channel or sunken area is left, this holds the

ink.ink. Intaglio is the term used to describe gravure Intaglio is the term used to describe gravure

printing (Italian for printing in a sunken printing (Italian for printing in a sunken surface)surface)

““Roto” GravureRoto” Gravure

Roto means Round.Roto means Round. Term used for Industrial Intaglio.Term used for Industrial Intaglio. Roto Gravure is printing from a cylinder.Roto Gravure is printing from a cylinder. Web Fed Web Fed Slitter ( devise used to cut sheets at the end of Slitter ( devise used to cut sheets at the end of

of the press)of the press)

Gravure IndustryGravure Industry

Simplest of all printing Simplest of all printing systems.systems.

Fastest press start up.Fastest press start up. Very little paper waste Very little paper waste

(half the paper waste of (half the paper waste of lithography).lithography).

Speed is extremely high.Speed is extremely high. 45,000 copies an hour.45,000 copies an hour.

Gravure Industry (continued)Gravure Industry (continued)

Some run 20 million copies without cylinder Some run 20 million copies without cylinder wearing out.wearing out.

Highest quality image.Highest quality image.

Industry OrganizationIndustry Organization

3 types of printing3 types of printing Packing PrintingPacking Printing Publication PrintingPublication Printing Specialty PrintingSpecialty Printing

Packaging PrintingPackaging Printing

This includes producing and folding.This includes producing and folding. CartonsCartons BoxesBoxes BagsBags Gift wrappersGift wrappers LabelsLabels

Publication PrintingPublication Printing

This includes PrintingThis includes Printing Newspaper SupplementsNewspaper Supplements MagazinesMagazines CatalogsCatalogs Mass Mailing AdvertisementsMass Mailing Advertisements

Specialty PrintingSpecialty Printing

Used to Print such materials asUsed to Print such materials as WallpaperWallpaper VinylVinyl Floor coveringFloor covering Textiles (decoration and clothing)Textiles (decoration and clothing)

Methods of Cylinder PrepMethods of Cylinder Prep

Diffusion etchDiffusion etch Direct TransferDirect Transfer Electromechanical ProcessElectromechanical Process Laser cuttingLaser cutting

Diffusion-Etch ProcessDiffusion-Etch Process

Image exposed much like developing a plate Image exposed much like developing a plate for regular offset printing except negative in for regular offset printing except negative in transferred.transferred.

Acid BathAcid Bath Copper cylinderCopper cylinder Cylinder then chromed (prolong life)Cylinder then chromed (prolong life)

Direct-TransferDirect-Transfer

Light Sensitive MaskLight Sensitive Mask Acid BathAcid Bath Chrome platingChrome plating

Electromechanical ProcessElectromechanical Process

Replaced chemical engravingReplaced chemical engraving Basically Done by a computerized mill that Basically Done by a computerized mill that

etches a digitally scanned image.etches a digitally scanned image.

Laser-cutting ProcessLaser-cutting Process

Chemically etched holes are made.Chemically etched holes are made. Plastic is used to cover holes.Plastic is used to cover holes. Same process as electromechanical is used Same process as electromechanical is used

except a laser does the cutting instead of a tool except a laser does the cutting instead of a tool bit.bit.

Well FormationWell Formation

Gravure Transfers from small wells that are Gravure Transfers from small wells that are etched or cut in the cylinderetched or cut in the cylinder

Cylinder rotates through a fountain of inkCylinder rotates through a fountain of ink Excess ink is wiped off by a doctor bladeExcess ink is wiped off by a doctor blade

Gravure Well VariablesGravure Well Variables

DepthDepth BottomBottom OpeningOpening BridgeBridge

DepthDepth

Bottom of the well to the top surface of the Bottom of the well to the top surface of the cylindercylinder

BottomBottom

Obviously the bottom of the wellObviously the bottom of the well

OpeningOpening

Distance across the wellDistance across the well

BridgeBridge

Surface of the cylinder between wellsSurface of the cylinder between wells

Well DesignWell Design

ConventionalConventional Wells have exactly the same opening sizeWells have exactly the same opening size Amount of ink is controlled only by the depth of the Amount of ink is controlled only by the depth of the

wellwell

Well Design (continued)Well Design (continued)

Lateral hard-dotLateral hard-dot Can create half tone imagesCan create half tone images Well opening sized differWell opening sized differ Well depth stays the sameWell depth stays the same

Cylinder ConstructionCylinder Construction

Most cylinder cores are made of steelMost cylinder cores are made of steel Some companies prefer aluminumSome companies prefer aluminum

Lighter Lighter Less expensive Less expensive Easier to shipEasier to ship

Cylinder DesignCylinder Design

Axis (center line of shaft)Axis (center line of shaft) Shaft (what the cylinder spins on)Shaft (what the cylinder spins on) DiameterDiameter Circumference (one impression)Circumference (one impression) Face Length (printing width)Face Length (printing width)

Two forms of CylindersTwo forms of Cylinders

Mandrel (removable shaft)Mandrel (removable shaft)

Integral (shaft mounted permanently) $$$$Integral (shaft mounted permanently) $$$$

General InfoGeneral Info

An impression roller presses paper to CylinderAn impression roller presses paper to Cylinder

Gravure printing allows high-quality images Gravure printing allows high-quality images on low-grade papers.on low-grade papers.