GB746574A - Photographic colour separation records for preparation of printing plates - Google Patents

Abstract

746,574. Photographic colour separation records. THORSLUND, O. E. G. June 19, 1954, No. 18076/54. Class 98 (2). Positive records for preparation of plates for the colour printing primarily of comic strips, drawings or simpler pictures, which are first provided in the form of positive drawings or outlines, or photographic black' and white, prints or half-tones, are made by placing a transparent material such as blank film on the origilial, colour painting this in tones of brilliance in inverse relation to the brilliance of the tones of a colour print to be produced and in colours partly coinciding with the colours of filters to be used in preparing the separation records, and photographing the painting in mirror-inverse manner against a non-reflecting background as of black cardboard through the filters to give separation records of positive character and suitable for photographic printing on to metal plates. Filters for two colour may be red and blue, for three colour red, green and blue. For white spaces the transparent material is left blank. In photographing, the reproduction camera is adjusted to take separations of correct size and a similar sized record for the black printer may be made by contact printing from a record prepared directly from the original. Instructions are provided for guidance of the artist in dealing with mixed shades. In some cases, the green separation record is used to make a yellow printing plate, with division into red, yellow and blue, but ordinarily two printing inks are used, greenish blue from the blue record and red-orange from the red record. Text to be printed is prepared in black against a white background and assembled with the blue record for eventual printing in greenish-blue or in this colour together with black when a black printer is used. Printing with more separations than the three colours and black is referred to.