Abstract: Process for forming an image on a substrate comprising applying an ink thereto by means of an ink-jet printer wherein the ink comprises a liquid medium and a phthalocyanine dye fraction obtainable by the fractionation of a solution and/or suspension of a mixture of phthalocyanine dyes of Formula (1), and salts thereof, by cross-flow filtration: wherein: M is 2H, copper or nickel; Pc represents a phthalocyanine nucleus; R1 and R3 independently are H or optionally substituted C1-4alkyl; R2 and R4 independently are H or optionally substituted hydrocarbyl; or R1 and R2, and, R3 and R4, independently, together with the nitrogen atom to which they are attached represent an optionally substituted aliphatic or aromatic ring system; x is 0 to 3.9; y is 0 to 3.9; z is 0.1 to 4; and the sum of (x+y+z) is 2.4 to 4.5.

Abstract: A metal chelate compound of Formula (1) or a salt thereof: [A-N=N—B] M ??Formula (1) wherein: A is an optionally substituted pyridyl ring; and B is of the Formula (2): wherein: X and W are substituents other than H; M is a metal chelated to A-N=N—B; and n is 0 to 4, also claimed are compositions and inks containing a compound of Formula (1), a process for ink jet printing using the inks and an ink jet printer cartridge containing the ink.