Patent ID: 7213516

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 and soluble or dispersible in ink and/or fountain solution; wherein said photosensitive layer exhibits an affinity or aversion substantially 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) exposing the plate with a laser according to digital imaging information to cause hardening of the photosensitive layer in the exposed areas; (c) overall applying to the exposed plate (i) a deactivating agent, (ii) heat, or (iii) a radiation that has a different wavelength from the laser and does not cause hardening of the photosensitive layer, to deactivate the photosensitive layer; and (d) contacting said deactivated plate with ink and/or fountain solution on a lithographic press to remove the photosensitive layer in the non-hardened areas and to lithographically print images from said plate to the receiving medium; wherein said steps (a) to (c) are performed with the plate under lightings (including darkness) that will not cause hardening of the photosensitive layer, and said step (d) is performed under a lighting that will cause hardening of the non-deactivated photosensitive layer.