Printed matter protected against colour copying by pattern - printed in light colour mixt. giving visibly different colour in copy

摘要

Printed matter protected against colour copying has at least 2 coloured patterns (5,7) of different colour, printed beside one antoehr. The colour of these patterns, defined by fractions of the primary colours of a yellow-magenta-cyan system, is such that each satisfies one of the following conditions: (a) one of the primary colours has a reflectivity (w.r.t. white) of over ca. 80%, whilst the other 2 primary colour have reflectivities of over ca. 40%; (b) one of the primary colours has fluorescence with a reflectivity of min. 100%; (c) all the primary colours have a reflectivity of over ca. 40%. The colour of at least one of the patterns satisfies condition (a) or (b). ADVANTAGE - Colour copies of this printed matter can be distinguished from the original, even if the copier is adjusted.