GB332276A - An improved process for the production of intaglio printing surfaces for intaglio printing of all kinds - Google Patents

Abstract

332,276. Klinger, R.. April 16, 1929. Etching.-In the production of intaglio printing-surfaces for the printing of pictures having half-tones, by the superficial etching of a metallic surface, the parts of the metallic surface to be subjected to the action of the etching medium are provided with a granulation which is etched into the depth by protecting the side,s of the grain while leaving the apices as well as the bottoms of the spaces between the individual grains exposed to the action of the etching medium. The preliminary graining of the surface may be effected in any known manner, after which it is inked slightly by a weak greasy ink, sprinkled with pulverized asphalt, and heated, so that the ink fuses and runs down the sides of the grains without entering the bottoms of the spaces between the grains. After the ink &c. have cooled and set the apices of the grains are exposed by scraping or grinding, whereupon an etching medium is applied.. The etching medium is preferably a known weak solution of iron chloride dissolved to a density of from 45-40‹ BeaumÚ. The printing-surface may be subjected to a preliminary etching prior to graining by the sand blast or other means, after which the etching by the above process is effected. Parts of a surface may be etched into the depth and the remaining portion etched in the usual manner.