The technique of photogravure
The technique of photogravure:
1.- The production of a copper plate photogravure can be divided into various phases: The elaboration of an enlarged continuous-tone positive, which is used to harden a dichromated-gelatin photo resist.
– The image is transferred to the copper plate, where it is developed in hot water.
– The copper plate, with the developed gelatin resist on top is covered with a rosin aquatint, and then etched in various baths of ferric chloride. Once etched, the plate is inked and printed by hand on an etching press.
2.Photopolymer: A polymer photo etching is a more contemporary technique employing a hybrid use of photo-polymer plates designed for relief flexographic printing as intaglio etching plates. A photographic positive (and sometimes a screen as well) is exposed to the photo-polymer and the image is developed out with water. The resulting plate can be printed as any normal etching plate would on an etching press.