Patent ID: 7645567

Claim:
A method of lithographically printing images on a receiving medium, comprising in order: (a) providing a lithographic plate comprising (i) a substrate, and (ii) a photosensitive layer capable of hardening upon exposure to a laser having a wavelength selected from 200 to 1200 nm; said photosensitive layer being soluble or dispersible in ink and/or fountain solution, and exhibiting an affinity or aversion opposite to the affinity or aversion of said substrate to at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink; (b) imagewise exposing said plate with said laser to cause hardening of the photosensitive layer in the exposed areas; (c) developing said exposed plate with ink and/or fountain solution to remove the photosensitive layer in the non-hardened areas; and (d) lithographically printing images from said plate to the receiving medium; (e) wherein said plate is mounted on the plate cylinder of a lithographic press for said exposure and development (steps b and c); and said press is in a pressroom with white room light and is shielded with covers that are non-transparent or only transparent to yellow or red light so that said plate is under a lighting that contains no radiation below a wavelength selected from 400 to 650 nm or in darkness during said exposure and development (steps b and c).