Visible light and infra-red heat are other factors that contribute to fading, which is why effective film installations must harness all three sunlight elements. Ultraviolet light rays bounce off solid objects-buildings, trees, streets, etc. Therefore regardless of a window’s compass orientation, you can still have a fading problem. Natural fibers like silk or wool are less fade resistant than synthetic fibers. Antiques, tapestries, rugs, etc., use less stable dyes and will fade more quickly. Fluorescent dyes are less color stable than other colors.