Abstract: The processability of polymer fibers, and more specifically of aramid fibers, was intended to be improved. This object was attained by the use of resin solutions or dispersions of resins in an organic solvent containing0.2 to 20 percent by weight of at least one polyamide resin based on long-chain branched dicarboxylic acids and having terminal carboxylic and/or amino groups,0.02 to 10 percent by weight of a copolymer compatible therewith and containing carboxylic acid and/or carboxylic acid anhydride groups and carboxylic acid esters,0 to 5 percent by weight of further auxiliary materials, andorganic solvents to make 100 percent by weight for the surface treatment of polymer fibers.