Flexible letter press printing plate

Abstract

A letter press printing plate is disclosed for wrapping around a drum. The printing surface is formed with a light-sensitive material layer on a metal backing plate with two different levels, the high level representing areas of solid or dark tones of printing and the low level representing areas of light tones of printing. The printing plate overcomes the problem of even transfer of ink from the solid or dark tones of printing areas and the light tones of printing areas. A method of forming the letter press printing plate is also disclosed wherein a photo polymer layer on a backing plate is first exposed to a negative representing areas of solid or dark tones and light tones of printing. The photo polymer layer is then dissolved away to the backing plate in areas where no printing occurs and formed into a two-level printing surface with the areas of solid or dark tones being at a high level and the areas of light tones being at a low level.

Dependencies are inferred from the claim text.