(Excerpt from ART HARDWARE: The Definitive Guide to Artists’ Materials, by Steven Saitzyk © 1987)
Below are several guidelines for safe picture hanging.
1. Do not hang a picture over a working fireplace. The exposure of artwork to the heat, smoke, and ash of a fireplace can result in serious damage. For artwork that is framed under glass and sealed from the atmosphere, you need only worry about the heat, which causes rapid acceleration of the aging process. Unprotected artwork will collect soot and will also be subject to the alkali of ash and the acids that result from the sulfur dioxide and hydrogen sulfide gases that are produced by the fire.
2. Do not hang a picture over a heater or under an air conditioner. Rapid changes in temperature, which are often accompanied by rapid changes in humidity, will cause premature aging.
3. Do not hang artwork on walls that are prone to dampness or mildew. Out-side walls of a house are more prone to dampness and to the development of mildew. When a piece of artwork is placed over a damp wall, the combination of dampness and darkness becomes a fertile ground for mold and mildew. Mildew is like cancer to artwork; once the artwork has it, it is difficult to get rid of it permanently.
4. Do not hang artwork where it will be exposed to direct sunlight. Avoid expo-sure to fluorescent lighting and strong indirect lighting. Light is the major cause of fading in artwork. Ultraviolet light, which is most concentrated in sunlight and fluorescent light, causes not only fading but unpredictable photochemical changes in artwork as well.