The invention relates to inks comprising a liquid medium and a compound of Formula (1): wherein: A and E are each independently optionally substituted phenylene or naphthylene groups; each M independently is a metal selected from Fe, Co, Cr, Cu, Ni, Zn, Al or Ti; and wherein the liquid medium comprises water and an organic solvent. The invention also relates to compounds of Formula (1) with the proviso that the optional substituents on A and E are not quaternary ammonium groups, to processes for making the same and processes for printing, e.g. ink-jet printing, using the ink.