GB744738A - Improvements in or relating to the printing of coloured pictures or the like - Google Patents

Abstract

744,738. Printing processes. LINDMARK, J. G. May 20,1954 [May 23, 1953], No. 14801/54. Class 100 (2). [Also in Group XV] A method of printing multi-coloured pictures or the like on a transparent base material comprises matting one surface of said material, and printing the differently coloured picture components laterally inverted on the matted surface and in the reverse of normal order, e.g. in the sequence black, red, blue and yellow, so that the final picture will be direct and correctly coloured as viewed through the base material. The surface may be matted by blasting with sand or other abrasive material. A transparent foil may be disposed on a drum rotated at high speed, while one or more sand-blasting nozzles maintained parallel and directed towards the drum are moved longitudinally of the drum in one direction at a constant, comparatively low velocity. After blasting, the dust is blown off and the foil is brushed off and flushed with a cleaning liquid, such as pure water. After printing, a continuous covering layer of white or other light colour may be applied in offset or by an ink-applying roller. The foil may be mounted on an opaque backing such as paper or cardboard by means of a white rubber latex paste, or on a transparent backing of a plastic foil by means of a colourless rubber latex paste. If the foil is to be mounted on thick paper or cardboard, it may be 0.2 mm. thick or less, while for use for open-air signs it may be up to 1 mm. or more thick. A protective sheet of a foil of the same material as the base may be adhesively applied to the printed surface. Printing may be carried out by a lithographic offset, letterpress or photogravure process. The method may be applied for printing coloured illustrations for written works, maps, book covers &c., signs and posters, or the lids of boxes for cigars, cosmetics, &c.