Method for obtaining a printing plate according to the silver salt diffusion transfer process

A method for making a lithographic printing plate according to the silver salt diffusion transfer process using a photographic material comprising on a support a silver halide emulsion layer and a layer containing physical development nuclei comprising the steps of:

• image-wise exposing said photographic material;
• developing a thus obtained image-wise exposed photographic material by guiding said image-wise exposed photographic material through an alkaline processing liquid comprising a hydrophobizing agent, in 15s or less and;
• directly thereafter guiding a thus obtained developed photographic material through a stabilising liquid wherein said stabilising liquid has a pH of from 5 to 7 and comprises a buffer;
• characterized in that said stabilising liquid comprises a compound having a mercapto-group having a pH.sub.a of 4.5 or less and corresponding to the following formula:
• ##STR17## wherein Z represents an alkyl, an aryl, an alkenyl, an alkynyl or a heterocyclic ring.