HAIR GLOSS 315 , ' ' I'" ,,!, ...... :'..:,,,,,,,,,,, I • J . untreated strands .•- • sprayed 0.2s sprayed 0.2s + 0.2s sprayed 0.2s + 0.2s + 0.4s Sample 3 Sample 2 Sample 2 Sample 1 Sample 1 Figure 17. Comparison of half-value angles in arbitrary units as a function of different spraying times and three different samples of gloss hair lacquers (sample 1 and sample 2 each applied on two different strands--sample 2 is identical with the sample in Figure 16). judged as the best. Comparison of the solid indicatrices of the untreated strands in Figures 15 and 16 again shows the difference between equally prepared strands and the necessity of measuring the same sample before and after treatment. Contrary to Figure 15, the solid line in Figure 16 shows a distinct maximum for a receptor angle of ½2 30 ø, which can be interpreted as surface reflection on the cuticle (ray C in Figure 5), and a second weak maximum at ½2 • 300- AccoMing to reference 2 and ray D in Figure 5, it may originate from a reflection at the opposite lying cuticle. The minor reflection is probably caused by the absorption loss in the fiber. Spraying the hair smoothes the fiber surface again. Most light seems now to be reflected from the lacquer surface (ray A in Figure 5), as in Figure 15. GLOSS AND STYLING GELS TREATMENTS The two last examples show the effect of so-called "gloss and styling gels." In Figure 18 the product was first used on a light base--a hair strand treated with both perm and hair bleaching--and in Figure 19 it's applied on undamaged hair. Although the initial indicatrices (solid curves) of both hair types differ in their shapes, a considerable and comparable improvement of the gloss parameters, indicatrix maximum, and half-value angle can be recognized immediately after application of the product. Moreover, it can be well recognized how the angle of the reflection maximum, originally displaced by 7 ø , moves to the specular direction at 30 ø . Here we get the same effect as

316 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS L o c e PHUP13N PH1P13N PH4P13N PHSP13N 1.80 120 0 6o o oo -50 +2'5.0 +55 0 +85 0 permanent waved and bleached hair additional treatment Gloss and Styling Gel, measured after 3 minutes measured after 2 5 hours measured after 21 hours R e c e p t o r c n g I e Figure 18. Indicatrix change caused by treatment with "gloss and styling gel" on a permanent-waved and bleached hair. L n (3 n c PHUPO4N PH1PO4N PH4PO4N PHSPO4N 900' 600. ,500. +25 0 +5'5,0 +85 0 undamaged dark brown hair additional treatment Gloss and Styling Gel, measured after 5 minutes measured after 2 $ hours measured after 21 hours 17 e c e p t o r c n g I e Figure 19. The same treatment as in Figure 18 on undamaged dark brown hair. by spraying with gloss hair lacquer. The reflection of the incident light occurs mainly on the gel surface, which smoothes the cuticles. Also, on undamaged dark brown hair, we achieve a remarkable gloss improvement compared to previous observations. After several hours, the improvement fades and disappears after one day. But the smoothing effect of the gel persists, and the indicatrix maximum is still at a receptor angle of ½2 • 0 ø 3 .