Inks and other compositions incorporating a polyesterurethane oligomer low viscosity, radiation curable.

A composition suitable inkjet ink, radiation curable, comprising: (A) 1 to 40 weight percent of an oligomer is a reaction product of ingredients comprising: (a) an aliphatic polyisocyanate comprising two or more isocyanate groups and (b) a radiation curable alcohol comprising one or more radiation curable moieties, one or more hydroxyl moieties, and one or more residues of polycaprolactone ester and (B) 60 to 90 weight percent of a reactive diluent; wherein the viscosity of the ink composition is up to about 50 centipoises (0, 05 Paus) at 25 ° C and wherein the ink composition is solvent.