Abstract: An improved process for preparing negative images from a photohardenable tonable element, wherein the unexposed photohardenable tonable element is tacky in a preselected temperature range, T.sub.1 -T.sub.2, in which temperature range the exposed photosensitive tonable element is nontacky but wherein the exposed element is retackifiable at elevated temperatures above T.sub.2. After imagewise exposure the unexposed areas have a colorless toning material applied to them at a temperature within the range T.sub.1 -T.sub.2 to make them nontacky at temperatures of at least up to T.sub.3, which is greater than T.sub.2. After heating to an elevated temperature above T.sub.2 but less than T.sub.3 the exposed areas have a contrasting toning material applied to them to give a negative or reverse image.

Abstract: Process for providing improved solvent resistant surfaces of relief flexographic printing plates prepared by imagewise exposure and liquid development of the unexposed areas of a layer of photosensitive elastomeric composition comprising a high molecular weight butadiene/acrylonitrile copolymer and a monomeric compound wherein, optionally after drying, the developed surface is, in either order, (1) postexposed to actinic radiation, and (2) contacted with two successive aqueous halogen solutions, first, 0.01 to 3.5% by weight aqueous bromine solution for about 15 seconds to 20 minutes or 0.2 to 10% by weight aqueous iodine solution for about 1.0 to 10 minutes, followed by chlorine solution equivalent to that supplied by an aqueous solution, 0.01 to 1.0 molar in NaOCl and 0.012 to 1.2 molar in HCl, for about 15 seconds to 5 minutes.

Abstract: Process for providing improved solvent resistant surfaces of relief flexographic printing plates prepared by imagewise exposure and liquid development of the unexposed areas of a layer of photosensitive elastomeric composition comprising a high molecular weight butadiene/acrylonitrile copolymer and a monomeric compound wherein, after drying, the developed surface is in either order (1) postexposed to actinic radiation, and (2) contacted with 0.01 to 3.5% by weight aqueous bromine solution for about 15 seconds to 20 minutes.