Disclosed herein is an aqueous coating material comprising (A) at least one polyurethane which is ionically stabilized, nonionically stabilized, or a combination thereof, and which is saturated, unsaturated, grafted with olefinically unsaturated compounds, or a combination thereof, (B) at least one wetting agent or dispersant; and (C) at least one organic solvent selected from the group consisting of dimethyl sulfoxide, sulfolane, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, hexyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, glycerol, solutions of trimethylolpropane, solutions of pentaerythritol, solutions of sorbitol, reactive polyether polyols with a number-average molecular weight of 110 to 6000 daltons and a hydroxyl number of 25 to 1000 mg KOH/g, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, glycerol ethoxylate, ethyl 3-ethoxypropionate, gamma-butyrolactone, N-(2-hydroxyethyl)piperidine, N-methylmorpholine, N-(2-hydroxyethyl)morpholine, N-acetylmorpholine, N-cyclohexylpyrrolidone, N-octyl-2-pyrrolidone, and a combination thereof. Also disclosed is a process for preparing the foregoing aqueous coating material.