PROCESS FOR THE MANUFACTURE OF A SCREENED PHOTOGRAPHIC COLOUR COPY WHICH SIMULATES A MULTI-COLOUR PRINT

摘要

1317874 Screened, photographic colour copy which simulates a multi-colour print CIBAGEIGY A G 21 July 1971 [24 July 1970] 34285/71 Heading G2C A screened or half-tone photographic colour copy which simulates a multi-colour print is prepared by successively exposing a lightsensitive negative-working colour photographic material to screened colour separation negatives of the original, which correspond to the colours blue, green and red through a colour filter of the same colour which was used to produce the colour separation negative, and processing to give a screened, positive direct-viewing colour copy containing colour images in yellow, magenta and cyan dyes respectively, the process being characterized in that the colour photographic material is subjected to at least one additional exposure to one of the screened colour separation negatives through a colour filter of a different colour from that used to produce the colour separation negative. The colour photographic material may be additionally exposed to white light or blue, green and red lights through a black and white negative of the original. The ratio of the exposure times of the or each additional exposure to the corresponding successive exposure(s) of the colour separations exposed with copying light of the same colour may be between 1:10 and 1:1. The negative-working photographic material may be a negative-working silver dye-bleach material (see Examples 1 and 3) or a negative-working chromogenic colour material (see Example 2).