248 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Topical Maneuvers per se Do Not Change Skin Surface Stiffness (Some Emollients Have "No Effect") DSR Subject Before* After % Change in DSR Subjective 1 5.9 6.1 3% Same 2 5.7 5.5 - 4% Same 3 6.7 6.4 - 4% Same *Subjects were "equilibrated" at 22øC, 15% RH for "before" measurement. Then an emollient cream product previously shown to have no effect on the DSR was applied. "After" was 5 minutes after product was applied. Subjective assesments were made at the same time. The cream is a commercial product the principal ingredients are safflower and sesame seed oils, glycerin, fatty acids, and elastin. and even though this residue technically is not oily or greasy, it may still be perceived as such by the consumer. Tautness or stiffness of the stratum corneum probably precedes some of the more apparent symptoms of dry skin. We therefore felt that it would be useful to know the magnitude of any instrumentally-measured change that would correspond to perceived changes in stiffness. Subjective appraisal of stiffness is derived from questionnaires such as the one shown in Figure 4, and instrumental measurements of stiffness were done with the GBE, as described. In Table I, we compare the DSR obtained on two sites on the face. It may be seen that the average value (stiffness) on the forehead is about twice that measured on the cheek. The range of value on forehead measurements Stiffening Effect of Soap & Water Outline of Protocol 1. Equilibration at 22C, 15% RH for I hour I I I I 2. Baseline Measurements I I I 3. Soap and Water Wash 1/2 Face "control" 1/2 rinsed only I ! I I 4. Reequilibrate 10 minutes at 22C, 15% RH I I I I 5. After-wash measurements Figure 7. Protocol for assessing the effects on skin surface stiffness of washing with soap and water.

FACIAL OILINESS AND DRYNESS 249 was also much wider. Measurements were done on the right and left sides of the face on six different subjects these are shown as paired values in the Table. It is clear that very different values may be obtained from what appear to be comparable contralateral sites. To assess product-induced effects, it was necessary to show that no inherent bias is introduced by topical applications. This was confirmed (Table II) by applying to the subjects' cheeks a cream which has no apparent effect on DSR. To measure changes brought about by some ordinary topical maneuvers, we tried soap and water washing, using the procedure outlined in Figure 7. As seen in Figure 8, the DSR varied substantially on contralateral sites on some individuals even though each Perceived Stiffness, left vs. right Cheek Forehead MUCH STIFFER MODERATELY STIFFER SLIGHTLY STIFFER EQUAL • • 1 2 3 4 5 6 SUBJECT 1 2 3 4 5 6 SUBJECT DSR, Percent Difference between left & right Sites Cheek Forehead +1oo +5o EQUAL 0 -50 -100 1 2 3 4 5 6 1 2 3 4 5 6 S U BJ ECT S U BJ ECT Figure 8. Perceived versus instrumentally measured stiffness (GBE) of the skin surface. For DSR, % difference = left-right/right x 100.