Patent ID: 8088561

Claim:
A method of making a lithographic printing plate comprising the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including an imaging layer, and, optionally, an intermediate layer between the imaging layer and the support, wherein the imaging layer includes a switchable polymer having a pendant hydrophobic group capable of being changed to a hydrophilic group by a chemical reaction upon exposure; b) image-wise exposing the coating, wherein the polymer having the pendant hydrophobic group undergoes a chemical reaction induced by the exposing step wherein the pendant hydrophobic group is changed to a hydrophilic group, thereby creating a lithographic image consisting of printing areas and non-printing areas wherein the non-printing areas are removable from the support by a gum solution; and c) developing the precursor by treating the coating of the precursor with the gum solution thereby removing the non-printing areas.