LIGHT-SENSITIVE LITHOGRAPHIC PRINTING PLATE PRECURSOR

摘要

The printing plate precursor is an aluminium support (1) with a hydrophilic surface and a photosensitive layer (2) formed thereon. The cut edges of the aluminium support are treated with a desensitizing solution, which is an aqueous solution containing a hydrophilic organic polymeric compound such as gum arabic, to form a layer (3) of the polymeric compound on the cut edges. The printing plate obtained from this precursor provides printed matter free of scumming at the parts corresponding to the edges of the plate.