Afro-textured hair chart below is the most commonly used chart to help determine hair types: Different ethnic groups have observable differences in the structure, density, and growth rate of hair. With regard to structure, all human hair has the same basic chemical composition in terms of keratin protein content. Franbourg "et al." have found that Black hair may differ in the distribution of lipids throughout the hair shaft. Classical afro-textured hair has been found to be not as densely concentrated on the scalp as other follical types. Specifically, the average density of afro-textured hair was found to be approximately 190 hairs per
Artificial nails polymer with "liquid monomer", usually ethyl methacrylate mixed with some inhibitor, forms a malleable bead. This mixture begins to cure immediately, continuing until completely solid in minutes. Another common material is acrylic gel, which contains photoinitiators that prevent its curing until exposed to either ultraviolet light within a certain wavelength. Some new techniques, too, have been invented, attempting to make obsolete the two outlined above. Dipping, for instance, involves painting nails with special primer and base coats, then repeatedly painting the nail with a clear coat and submerging it in powder. Nail products are available in a variety of colors