Ira W. Rubel

The offset plate is usually of zinc or aluminum or a combination of metals, with the surface treated to render it porous and then coated with a photosensitive material. Exposure to an image hardens the coating on printing areas; the coating on nonprinting areas is…

…New Jersey, an American printer, Ira W. Rubel, discovered that an image accidentally transferred from the plate cylinder of his rotary to the rubber blanket of the impression cylinder during a paper-feed stoppage could itself be used for printing and in fact produced a superior impression. Rubel and an associate…