Pigment compositions

摘要

The invention provides a pigment composition comprising a pigment having adsorbed on its surface, or as a physical mixture, up to 10% by weight, based on the total weight of pigment composition of a coding compound which is a compound containing an azo, azomethine or polycyclic chromophore and which has an absorption spectrum and a Raman spectrum different from that of the pigment. The compositions are suitable for use in printing inks for security applications.