GB375774A - An improved method of printing - Google Patents

Abstract

375,774. Printing processes ; etching. BERIAU, O. A., 14, Elgin Street, Quebec, Canada. Feb. 27, 1931, No. 6117. Convention date, March 1, 1930. Drawings to Specification. [Class 100. (ii).] A process for obtaining printing-plates for reproducing the natural appearance and colours of marble and other materials consists in selectively etching the surface of the material by chemical agents to form relief designs, and transferring the designs in acid-resisting ink to form metal printing-plates by, etching ; a grain or screen plate is formed from the first etching of the material and colour-printing plates from successive etchings thereof. A slab of.marble, having'for example white, green, and red components, is etched in hydrochloric acid to develop the grain, and the etched surface is used to produce a metal printing-plate The'surface is then selectively etched for the white components, duplicate metal plates are deep etched in this design, and the depressions in these plates, corresponding to the white components, are filled in with acid resist. A further selective etching of the slab, attacking the green components, leaves the red design in relief. This design is transferred in acid resisting ink to one of the duplicate metal plates, which is then deep etched to form the red colour plate. This plate is also used to apply to the complementary plate a red design in soluble ink, after which the complementary plate is coated all over with acid-resisting ink, treated with water or other solvent to remove the parts of the coating over the soluble ink, and then deep etched to form the green colour plate. The grain or screen plate obtained from the first etching is used to apply a relatively light impression in black or other shade, either as the first impression on a selected ground colour, or as the final impression after the colour impressions, and is also used to form a grained surface on the two colour plates. The plates may be used directly for printing, or transfers, stereotypes, electrotypes, intaglio plates, or lithographic plates may be made therefrom.