An excerpt from "Caring for your Treasures" from the American Institute for Conservation of Historic and Artistic Works.
Paintings are fragile creations that require special care to ensure their continued preservation.
It is important to maintain a proper environment for your paintings. The structural components of a painting expand and contract in different ways as the surrounding temperature and humidity fluctuate. For example, the flexible canvas may become slack or taut in a changing environment, while the more brittle paint may crack, curl, or loosen its attachment to the underlying layers. Paintings generally do well in environmental conditions that are comfortable for people, with relative humidity levels between 40 and 60 percent.
For the full article, please visit: http://www.conservation-us.org/index.cfm?fuseaction=Page.ViewPage&PageID=632