An ink-jet printing process for printing textile fibre materials, wherein the fiber materials are printed with an aqueous ink comprising (I) at least one anionic acid dye, and (II) dipropylene glycol, said ink having a viscosity of from 5 to 20 mPa s at 25.degree. C., and wherein the said ink is applied to the fiber material with an ink-jet print head comprising an ink supply layer (b) receiving ink from an external ink reservoir, said ink supply layer having a first side and a second side and comprising, a porous medium having a plurality of pores therein and a plurality of holes extending therethrough, so as to allow passage of the ink allows for high speed printing and yields prints with good fastness properties.