Light can harm most any collectible, especially organic materials like wood, paper and textiles. In addition to fading colors in prints and fabrics, harsh light can dry out many materials and can speed up chemical reactions that occur naturally over time.
All collections should be displayed away from direct sunlight. Even things that seem indestructible, like plastics, can melt when stored near a sunny window. Lights in display cabinets should be used sparingly as well. Turning display lights on when the air feels a bit damp can help alleviate humidity, however.
In general, light levels should be fairly low for most collectibles so displaying them in a hallway or specific room with adequate window coverings can help. For those serious about protecting collections, light meters can be purchased at photo supply shops so you can test exactly how much potentially harmful light might be filtering into your home.
When it comes to humidity, a good balance remains important for most antiques and collectibles. When there's not enough humidity, items like paintings, wood and paper can shrink, crack and become very brittle. When humidity reaches excessive levels, rust can develop on metal items, mold can grow on a variety of objects and insects are encouraged to breed.
If you're not sure about the humidity levels in your storage areas, you can also test this with a hygrometer available at most hardware stores. Humidity should be at about 50% whenever possible.
Another consideration is temperature. Avoid the extreme temperature fluctuations of storing collectibles in attics or garages, especially where organic materials like wood, paper and cloth made of natural fibers are involved. The ideal temperature for preservation hovers around 64 degrees. That's a little cold for most people, but keeping your home and storage areas as cool as you can afford while remaining comfortable is preferable.
If you have one room in your home that tends to be a little cooler than the rest of the house year round, that's going to be your best spot for displaying and storing collections. Again, hallways and dimly lit rooms seem to provide a little more coolness so consider those areas for fragile items like ephemera and textiles.
Change Climates Gradually
If you decide to change the way you are storing items, moving from hot to cold and vice versa, do so gradually. Most antiques can be shocked when exposed to temperature extremes too quickly. For example, when exposed to extreme temperature changes the tiny cracks in the glaze of ceramics, called crazing, can appear more rapidly than they would have naturally.
Glass items can crack as well when exposed to extreme temperature changes, along with glass components used in a number of different types of collectibles.
See page two for information on cleaning your antiques and collectibles.