Patent ID: 7456277

Claim:
A method of minimizing absorption of visible light in an ink composition comprising an IR-absorbing dye, said method comprising preselecting said dye from a metal-cyanine of formula (I): Q 1 , Q 2 , Q 3 and Q 4 are the same or different and are independently selected from a C 3-20 arylene group or a C 3-20 heteroarylene group; M is selected from Si(A 1 )(A 2 ), Ge(A 1 )(A 2 ), Ga(A 1 ), Al(A 1 ), Mn(A 1 ), Fe(A 1 ), Sn(A 1 )(A 2 ), Pb(A 1 )(A 2 ); A 1 and A 2 may be the same or different and are axial ligands comprising a group for reducing π-π interactions between adjacent dye molecules.