BASE MATERIAL MADE OF PLATE-SHAPED, SHEET-SHAPED OR BELTLIKE ALUMINUM OR ITS ALLOY FOR OFFSET PRINTING PLATE, ITS MANUFACTURE AND MANUFACTURE OF OFFSET PRINTING PLATE, ONE SURFACE OR BOTH SURFACE THEREOF HAS PHOTOSENSITIVE FILM

摘要

An improved substrate suitable for use as a base for a lithographic printing plate, especially a plate useful for the production of continuous tone images. The substrate is produced by extremely uniformly graining an aluminum sheet which has a highly polished, mirror- like surface.