Abstract: A process for printing synthetic thermoplastic fibers, particularly polyester textiles, by applying to the fibers an aqueous dispersion of a non-ionic organic colorant, particularly a disperse dyestuff, and a thickener, subsequently drying the printed fibers, and finally heating the fibers to fix the colorant, wherein the aqueous dispersion contains less than 1%, preferably 0.2 to 0.5%, of a thickener of the formula ##STR1## WHERE R is hydrogen or lower alkyl,R.sup.1 and R.sup.2 are hydrogen, sodium, potassium, ammonium, mono-lower alkyl ammonium, di-lower alkyl ammonium, tri-lower alkyl ammonium, or tetra-lower alkyl ammonium,M is 0 or 1,N is 2 - m, andY is 5000 to 50,000.Textiles printed by this process do not require any soaping or afterwash to remove the thickener and any unfixed dyestuff in order to have full shade printings with excellent fastness properties.