GB825093A - A method for polychromatic photomechanical printing - Google Patents

Abstract

825,093. Polychromatic photomechanical printing. IMPRIMERIE CINO DEL DUCA. Feb. 25, 1957 [Feb. 24, 1956], No. 6255/57. Drawings to Specification. Class 98(2) Printing in colour as from a drawing or photograph in black and white is effected by making an ordinary negative of the subject, drawing or photograph; printing a number of positives therefrom on paper or film having a red or other inactinically coloured background, applying on each of these positives a layer of gouache of graded intensity on areas which are to be reproduced in variable intensity, each positive corresponding to one colour such as blue, red and yellow; obtaining from these positives reverse representations in black and white in which the gouache treated areas only show up, the inactinic background and black lines giving white or transparent parts; making from these reversed representations, of positives on printing surfaces which are to be inked with the respective colours; printing from the initial negative of a positive in black and white comprising the lines and black parts, and also legends which are to appear in the final result and preparing a corresponding printing surface; and printing from these several printing surfaces in register. An example is directed to the photographic operations and those concerning the application of gouache, with indication of 'final reproduction by photogravure from engraved cylinders.