Abstract: A visible radiation sensitive composition is described which comprises a binder, one or more polymerizable compounds containing at least one polymerizable group, and one or more dyes having an absorption range in the emission range of the radiation source, characterized in that said composition comprises as an initiator an initiator system consisting of a metallocene as a photoinitiator and an onium compound as a coinitiator. The visible radiation sensitive composition shows an increased radiation sensitivity compared to the known radiation sensitive compositions and is especially suitable for recording materials such as printing plates, which can, in particular, also be exposed by means of laser radiation in the visible range.

Abstract: A process for producing a planographic printing plate comprising subjecting a light sensitive planographic printing plate member to a burning in wherein the light sensitive planographic printing plate member is treated with an aqueous solution of the reaction product of naphthalene, formaldehyde, and sulfuric acid prior to such burning in treatment.