A fixer fluid composition, for inkjet printing, and ink set containing it. A disclosed example fixer fluid composition includes up to about 1.5 wt % of surfactants, from about 1 to about 20 wt % of humectants, from about 3 to about 16 wt % of a metal carboxylate salt as fixer agent, and an acid in view of adjusting the pH of said composition to a pH between about 5.0 and about 7.0. A disclosed example of ink set includes, at least, an ink composition including a colorant dispersed in an ink vehicle and said fixer fluid.