Hair Ethnicity 202 lipids in biological tissues, it has been limited by its resolution of 225 ([µ]m)2. The use of a synchrotron infrared microscope with a resolution of 9 ([µ]m)2 yields the ability to profile lipids across transverse sections of hair. A study utilizing the synchrotron source found a high concentration of fatty acids in the medulla, and to a lesser extent, in the cuticle. A comparison of samples before and after extensive soxhlet extraction revealed significant differences for the Caucasian hair, but a similar result was not obtained for the African hair. This led the authors to speculate that either the lipids were absent from African hair or much less significant than in the Caucasian hair.29 Physical Attributes Surface properties: Hair shine is a standard measurement in the cosmetics industry, and optical properties of hair are important to understand from both qualitative and quantitative perspectives. Consumers use hair shine as one of the most significant visual cues in assessing healthy hair. The shine in hair that can either be perceived or measured is based on the amount of specular and diffuse light that is reflected towards the detector (eyes or instrument) and its intensity is related to hair color, surface properties and geometry. In the world of optics, lighter and brighter colors on flat dense surfaces reflect more light so they appear to be shinier. However, with hair, darker colors usually appear to be shiner than those that are lighter because when light enters the lighter fibers, it is scattered off interior irregularities so the diffuse reflectance is increased, which diminishes shininess. The amount of diffuse light decreases in darker hair due to absorption which increases the amount of shine.32,33 Therefore, hair from the Scandinavian region, which has a large population of people with blond hair, is perceived to be less shiny compared to hair with darker pigments like those from African and Asian descent. The morphology of the hair surface not only dictates its appearance but it influences its level of protection. The cuticle