The present invention provides an IR-absorbing dye of formula (I) or (II) wherein R10, R13, R20, R23, R30, R33, R40 and R43 are independently selected from a C1-12
alkyl group bearing a hydrophilic or hydrophilizable group; R11, R12, R21, R22, R31, R32, R41 and R42 are independently selected from H or a C1-30 hydrocarbyl group, or each of R11 / R12, R21 / R22, R31 / R32, and R41 / R42 are together joined to form a C3-30 hydrocarbylene group; 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 intermolecular interactions; R3 is a selected from C1-12
alkyl, C5-12
aryl, C5-12 arylalkyl or Si(Rx)(Ry)(Rz); and Rx, 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.