Process for the production of printing plates

A process for producing a lithographic printing plate from a ligh-sensitive element comprising a support having a hydrophilic surface, a non-silver light-sensitive layer on the support which forms a water-insoluble lipophilic image and a gelatino-silver halide light-sensitive emulsion layer on the non-silver light-sensitive layer, comprising the steps of:

• (a) imagewise exposing the element to light, to which the gelatino-silver halide light-sensitive layer is sensitive, in order to form a latent image on the gelatino-silver halide light-sensitive emulsion layer;
• (b) developing the element to form a silver image on the gelatino-silver halide light-sensitive emulsion layer;
• (c) exposing the element to radiation, to which the non-silver light-sensitive layer is sensitive, in order to form the water-insoluble lipophilic image on the non-silver light-sensitive layer;
• (d) washing the element in an aqueous solution containing 0.001% to 10% by weight of proteolytic enzyme at a temperature of from 20.degree. C. to 60.degree. C. for 10 to 60 seconds in order to wash out the developed gelatino-silver halide light-sensitive emulsion layer;
• (e) developing the non-silver light-sensitive layer to remove either exposed area or unexposed area of said non-silver light-sensitive layer thereby obtaining a lithographic plate comprising the water-insoluble lipophilic image.