Clothing specifically designed to avoid sun exposure should be incorporated into a comprehensive sun-protection program. Transmission of UV radiation through fibers depends on the radiation that is absorbed by the fiber and scattered by the fiber. Polyester
provides more protection than cotton. The cover factor, defined as the ratio of closed spaces to open spaces in the fabric, is the most important factor in determining the photoprotection of the fabric (46). Darker colors provide better protection than lighter colors. To enhance the ultraviolet protection factor (UPF) of clothes, UV-absorbing laundry detergents have been shown to increase the UPF of a cotton T-shirt by 400% (47).