Method of minimizing absorption of visible light in ink compositions comprising infrared-absorbing macrocyclic cyanine dyes

摘要

The present invention provides a method of minimizing absorption of visible light in an ink composition comprising an IR-absorbing metal cyanine dye, said method comprising preselecting said dye such that said metal has at least one axial ligand bound thereto, wherein said axial ligand comprises a moiety suitable for reducing intermolecular interactions between adjacent dye molecules. The method is especially suitable for use in connection with netpage and Hyperlabel systems.