The present invention provides an IR-absorbing dye of formula (I) or (II):whereinQ1, Q2, Q3 and Q4 are the same or different and are independently selected from a C3-20 heteroarylene group comprising at least one N atom;M is selected from Si(A1)(A2), Ge(A1)(A2), Ga(A1), Mg, Al(A1), TiO, Ti(A1)(A2), ZrO, Zr(A1)(A2), VO, V(A1)(A2), Mn, Mn(A1), Fe, Fe(A1), Co, Ni, Cu, Zn, Sn, Sn(A1)(A2), Pb, Pb(A1)(A2), Pd and Pt;A1 and A2 are axial ligands, which may be the same or different, and are selected from —OH,
halogen, —OR3, a hydrophilic ligand and / or a ligand suitable for reducing cofacial interactions;R3 is a selected from C1-12
alkyl, C5-12
aryl, C5-12 arylalkyl or Si(Rx)(Ry)(Rz); andRx, Ry and Rz may be the same or different and are selected from C1-12
alkyl, C5-12
aryl, C5-12 arylalkyl, C1-12 alkoxy, C5-12 aryloxy or C5-12 arylalkoxy.Dyes of this type are especially suitable for use in netpage and Hyperlabel systems.