2008 TRI/PRINCETON CONFERENCE 195 Figure 10. Change in apparent cuticle angle after conditioner treatment. Figure 11. Changes in shine values and apparent cuticle angles after PBEM spray treatment (light bleached hair). Figure 12. Changes in shine values and apparent cuticle angles after PBEM spray treatment (medium brown hair).

JOURNAL OF COSMETIC SCIENCE 196 Figure 13. Change in blond hair shine values from three commercial shampoo products. SHINE PERFORMANCE OF THREE COMMERCIAL SHAMPOO PRODUCTS Three commercial shampoos were evaluated to determine whether the SAMBA system can detect changes in shine after different shampoo treatments, Experiments were conducted on virgin blond hair. Average change in hair shine index for each of the shampoos was 9.73%, 7.9% and 2.04%, respectively (Figure 13). It can be seen that only shampoos 1 and 2 improved hair shine on blond hair signifi cantly. SHINE PERFORMANCE OF SHAMPOO AND CONDITIONER It is interesting to note that SAMBA measurements demonstrated that shampoo samples provided better shine enhancement than the corresponding shine conditioner. Since a shampoo frees the hair surface from foreign residue, the cleaned surface will generate stronger specular light intensity, therefore, enhancing shine. If the shampoo formula not only cleans the hair surface, but also deposits some thin smooth fi lm such silicone oil or PBEM on hair surface, it will result in more surface shine. In contrast, the main purpose of hair conditioner is to deposit conditioning agents onto the hair surface such as cationic surfactants (polymers), silicone oil, fatty alcohol, etc. There always is a competitive depo- sition between conditioning agent and shine-enhancing agent, which will reduce the amount of shine-enhancing agent on hair surface and may also generate an uneven- distributed fi lm. If the deposited substance does not form a thin and uniform (evenly distributed) fi lm on hair surface, it will not improve the surface specular light intensity. In fact, in many cases, the depositions reduce hair shine because of the increased light scat- tering by the non-smooth surface and discontinuous spots of substance depositions. This may explain why a conditioner is less effective in hair shine enhancement than a shampoo. CONCLUSIONS We have established an experimental protocol for the evaluation of hair shine index (lus- ter) and surface apparent cuticle angle of hair samples treated with rinse-off products (shampoo and conditioner), and successfully applied the protocol to study the effects of shampoos, conditioners and hair spray products. We demonstrated that addition of 2%