PRINTING FORM PRECURSOR AND METHOD OF PRINTING

摘要

A printing form precursor comprises a printing surface which comprises an anodic layer which is hydrophobic and capable of being made hydrophilic by fast laser pulses but capable of becoming hydrophobic again, preferably for re-use, if desired. These changes are influenced by thickness of the anodic layer, and by alloying elements in the anodic layer. Benefit is gained also from using a darkly coloured anodic layer and by permitting the change from hydrophilic to hydrophobic to take place in a carbonaceous or siliceous atmosphere. By such means the invention achieves the goal of providing a printing form precursor which does not need a chemical developer, and which can be used multiple times, to print different images.