n. (also UV filter)a material that absorbs ultraviolet radiationLeisinger 1963, 77Ultraviolet filters, temperature and humidity controls, filtered air-conditioning systems, electronic alarms, and good exhibit equipment have made the permanent or semipermanent exhibit a possibility.Bresee 1986The use of ultraviolet filters over light sources in buildings housing textile collections has been shown to decrease the damage caused by photochemical degradation.Crews 1989, 122Four types of ultraviolet filters were evaluated for their effectiveness in reducing fading of wool dyed with selected natural dyes and one synthetic dye. . . . The control specimens colored yellow with the weld dye retained more of their yellow color because of the yellowing of the wool substrate whereas the weld-dyed specimens exposed to light behind UV filter underwent no yellowing, only fading caused by the visible radiation. McCabe 1991A room was specially renovated for the storage of photographic holdings of high intrinsic value, including these 19th-century negatives. . . . Fluorescent light fixtures are equipped with ultraviolet filters.Kerr, Capjack, and Fedosejevs 2000, 346Because the action of light is cumulative, reducing the illuminance and exposure time and screening out the most harmful UV rays may slow light damage to objects. For storage areas, Garry Thomson (1986) suggests that a good UV filter should transmit less than 1% of the incident radiation between 320 and 380 nm. Fabric covers are sometimes used to protect objects from UV, visible light, and dust in conservation laboratories and museums.Ritzenthaler 2010, 137Ultraviolet filters, which contain UV absorbers, are available in many forms, including rigid acrylic sheets, flexible film or foil (either polyester or acetate), or as a coating or varnish. Plain window glass will filter UV radiation below 325 nanometers but transmits UV radiation between 325 and 400 nanometers (it is possible, however, to have glass sandwiches custom-made with a UV filtering film interlayer). To be effective, a UV filter must be well fitted to ensure that all light passes through the filter rather than leaking out at its edges.NEDCC 2020a, 2In addition, ultraviolet filters should be installed to control this damaging component of light. UV-filtering panels can be used in windows, cases, or frames.
Notes
Filters are used between light sources and archival resouces to reduce degradation from ultraviolet radiation (also known as ultraviolet light). Common forms of ultraviolet filters include film placed on windows or plastic shields placed around fluorescent bulbs.
