Many organic materials, such as carpet, fabrics, paper, artwork, paints, and wood may fade upon exposure to sunlight. Window selection can influence the type and intensity of transmitted radiation. The most harmful radiation in sunlight are the ultraviolet (UV) rays, which are the most energetic and thus most likely to break chemical bonds, leading to fading and degradation. Glass blocks all UV radiation below 300 nm, but transmits UV from 300-380 nm. Coatings on glass can reduce the UV transmitted by up to 75 percent. UV absorbers can be incorporated into thin plastic films in multilayer windows or as an interlayer in laminated glass. In both cases, the UV transmission can be reduced to less than 1 percent. However, it is important to note that the remaining visible light that is transmitted can still cause serious fading in some materials. Using Low-E coated glass or windows incorporating plastic layers rather than clear uncoated glass will reduce fading for many modern interior furnishings.

Note: Damage-weighted transmission includes ultraviolet and visible light. All values are for glazing unit only without frame. Source: Lawrence Berkeley National Laboratory.