| 摘要 |
444,229. Photomechanical colour printing - surfaces. FEENY, V. F., 73A, Queen Victoria Street, London.-(Miehle Printing Press & Manufacturing Co. ; 14th Street, Chicago, U.S.A.) March 25, 1935, No. 9240. [Class 98 (ii)] Printing surfaces for three-colour printing are prepared from three colour separation negatives, for red, blue, and yellow respectively, by making positive transparencies of the three negatives, printing from the blue positive superimposed on the yellow negative to make a corrected yellow positive, from the blue positive superimposed on the red negative for a red positive, and from the yellow positive superimposed on the blue negative for a blue positive, the printing plates being made from the corrected positives. Two corrected positives for different shades of the same colour, e.g. pink and red may be made in the case of the red and blue negatives and a black and a grey plate from an additional non-colour separation negative. The latter may be prepared by successive partial exposures through green and orange filters. If desired, the half-tone screen may be combined with the superimposed negatives in making the corrected positives with or without the interposition of a plane glass plate. Contact printing by means of a concentrated beam of light from a distance, may be used. Projection printing may also be employed and the half-tone screen may be used at a later stage of the process.
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