Amphipathic copolymer pigment dispersants

An amphipathic co-polymer pigment dispersant having a weight average molecular weight of from 2,500 to 20,000 inclusive and comprising:

• an addition polymer backbone having at least one stabilizer unit selected from the group consisting of:
• C.sub.1-4 alkoxy polyethylene glycol acrylate,
• C.sub.1-4 alkoxy polyethylene glycol methacrylate,
• C.sub.1-4 alkoxy polyethylene co-propylene acrylate ester, and
• C.sub.1-4 alkoxy polyethylene co-propylene methacrylate ester;
• where the backbone comprises up to 30% by weight of non-functional structural units and at least 70% by weight in total of said stabilizer units and functional unit, where the functional units are:
• (a) styrene units where the styrene is substituted or unsubstituted styrene;
• (b) hydroxy group-containing units, and
• (c) carboxyl group-containing units, such that the molar proportion per one mole of hydroxy units are from 0.1 to 26.1 moles of carboxyl units, from 0.28 to 25 moles of styrene units, and from 0.8 to 66.1 moles propylene-oxy or ethylene-oxy groups, respectively.