Patent ID: 8088560

Claim:
A method of making a lithographic printing plate comprising the steps of: (a) providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, and a coating on the support, the coating comprising (i) at least one image-recording layer which includes a photocurable composition, the composition including a compound which is capable of forming free radicals upon image-wise exposure, and (ii) on top thereof, an oxygen-barrier layer including a water-soluble or water-swellable polymer; (b) image-wise exposing the coating by a laser in a plate setter; (c) optionally, heating the precursor in a pre-heating unit; (d) treating the image-wise exposed precursor in a developing unit wherein water or an aqueous solution is supplied to the coating of the precursor, wherein the oxygen-barrier layer and a portion of the image-recording layer are removed from the support at the non-exposed areas, thereby increasing the oxygen permeability of the remaining portion of the image-recording layer to such an extent that curing of the non-exposed areas of the coating by ambient light is inhibited by quenching of free radicals with oxygen, and the remaining portion of the image-recording layer protects the hydrophilic surface; (e) mounting the treated precursor on a plate cylinder of a lithographic printing press; and (f) developing the precursor by rotating the plate cylinder while feeding dampening liquid and/or ink to the coating, thereby removing the remaining portion of the image-recording layer at the non-exposed areas; wherein the plate setter is mechanically coupled to the developing unit of step (d) by a conveying device such that the precursor is shielded from ambient light.