A set of 7 surfaces were used as stimuli in a scaling experiment. For 10 Ss individual scales were obtained, by a method of ratio estimation, for (a) roughness, (b) smoothness, and (c) preference. The main results were: (a) For all Ss roughness was approximately a power function of the physical stimulus variable denned as the coefficient of friction. The exponent of the function varied greatly between Ss but exceeded 1 in almost all cases, (b) For nearly all Ss smoothness was approximately the inverse of roughness, (c) For nearly all Ss preference was directly proportional to smoothness.