Flat print plate with layer of soft electrically insulating material - has extra layer with dispersed migration particles developing image by weakening

摘要

Printing plate for flat printing using a photographic plate (10) with a layer of electrically insulating material (12) that can be weakend. The material has a layer (13) on, or near the surface which contains migrating particles. The particles are dispersed throughout the layer. The migrating particles and the substrate (11) possess diverging hygroscopic properties. Latent electrostatic images are formed on the surface of the photographic plate. Their images are developed by the weakening of the soft layer and from an image of migrating particles on the substrate. The image zones will have a different affinity to water than the background zones.