Process for reducing halftone dot images

Claim 1

A process for reducing the size of the dots of a halftone dot image comprising: (1) imagewise exposing, using active radiation, a metal image-forming material comprising (a) a support, (b) a thin metallic layer comprised mainly of aluminum on said support, which thin metallic layer is dissolved in the alkaline developer solution of step (2), and (c) a photosensitive resin layer on said thin metallic layer, which photosensitive resin layer is dissolved or swollen and selectively removed at exposed or unexposed areas by contact with the alkaline developer solution of step (2); (2) developing said image-wise exposed metal image-forming material with an alkaline developer solution to cause the dissolving of the thin metallic layer and the dissolving or swelling and selective removal of the photosensitive resin layer, a half-tone dot image resulting upon development of the photosensitive resin layer; (3) applying a solution which is effective only to swell the photosensitive resin layer but which at most has only a slight capability to etch the halftone dot image at those parts of said metal image-forming material in which the size of the halftone dots is to be reduced, thereby swelling the photosensitive resin; and then (4) applying to said metal image-forming material a reducing solution which reduces the size of said dots comprising the half-tone image, the reducing solution permeating between the support and the photosensitive resin layer to contact the thin metallic layer at sites where the thin metallic layer does not contact the photosensitive resin layer or the support and etching the thin metallic layer.