It can't be brass, because it's green. Copper is green.
The process is some form of intaglio, the opposite of letterpress. I think rotogravure.
With gravure, the plate has to be fairly thick, because the image gets cut into the plate. Sometimes the image itself is as much as an eighth of an inch below the surface, although usually it's like a sixtyfourth. The ink is forced in, then wiped off, and that's how the impression is done.
Engraving is intaglio, and so is etching, but etching uses something like acid.
The force which is needed to press the ink into the paper is very great, so the machinery needs to be very heavy. The little gravure presses were failures because they were so expensive, and about the same time, Multilith came out with the 1250, which was the first really useable small offset press.
Justin thinks it's off a small rotogravure press. (Thanks, Justin.) |
