From moths to mildew to sunlight, collectibles are threatened by seen and unseen forces all around them. Even G.I. Joe can't combat these relentless assaults without some back-up in the form of an informed collector.

In the battle against the elements, collectors are not just feeling paranoid; there really are forces out to get them. Bugs chew holes in shawls. Mold creeps incessantly through the pages of old magazines. Sunlight yellows photographs. Heat warps records.

Even different regions of the United States have their own arsenal of environmental weapons with which to attack prized possessions.

"The South is probably the hardest on collectibles because of the high humidity," said conservator Carol Turchan of the Chicago Historical Society. "It also has more insects that eat mold on objects or devour different kinds of materials."

Though the South is sultry, the Northern states present their own problems, as the climate alternates between 95-degree, humid summer days and the dry, below-zero days of winter.

"Count your blessings if you live in the Southwest," said Todd Haefer, associate editor of eBay Magazine. "Experts agree that its steady, low humidity is ideal for preservation."

However, no matter what region you call home, there are enemies of the collectible common to all locations.

Light, both the rays of the sun and artificial illumination, can take its toll on all types of collectibles. Fabrics, printed materials, and painted objects fade or discolor. Just as sunlight can burn and wrinkle our skin, it dries out and deteriorates a variety of collectibles.

"Its immediate effect on the molecular level can yellow paper, and the damage is irreversible," said Craig Deller of Deller Conservation Group Ltd. in Geneva, Ill.

Keep items especially organic-based ones out of direct sunlight. Incandescent light produced by the ordinary household light bulb is preferred over fluorescent lighting. Light bulbs produce a lot of heat, so place items a good distance away to avoid damage.

Temperature and humidity, crucial elements of preserving stored items, can impact the actual item and, in certain combinations, provide an environment where destructive insects, mold, fungus, and mildew thrive.

The preferred humidity range for storage is between 45 and 55 percent. Humidity readings above 65 percent fall within the danger zone.

Too dry an environment, especially combined with a high temperature, can dehydrate materials. Surface darkening, color changes, cracking, buckling, and flaking are all signs of too dry an environment.

Don't store valuable items in the garage or attic, where they can experience extremes of both temperature and humidity. Extreme swings between damp and dry conditions can cause veneer and joints on furniture to loosen or cracks to form. Items stored near fireplaces, radiators or heat vents will often crack.

Be cautious about storing items in a basement. Finished basements that are dry and insulated may be OK, but check humidity levels frequently and use a dehumidifier if necessary.

Though the bugs a collector battles may not rank up there with the giant irradiated ants that threatened mankind in the film Them, some common pests can wreak havoc with a collection of anything that has an organic element to it.

A major myth is that cedar wood will prevent damage from the clothes moths that wage "holey" wars on wool and silk.

"Cedar is not a good idea," said Turchan. "It's no real guarantee against bugs and gives off vapors that could be harmful to materials."

Silverfish, known for devouring paper, and book lice, which feed on mold that grows on books, are both signs of too damp an environment. Keeping humidity and temperature levels moderate is the best way to discourage these pests.

The storage materials a collector uses to protect items from light and bugs may still end in disaster because of chemical reactions that can occur.

Avoid the everyday cardboard box, which is treated with acid. Use acid-free storage boxes that contain chalk to neutralize the acid. These are the best choices for paper products, Turchan said.

The chemical processes used to create many plastic storage materials may also result in yellowing of collectibles. Because the items are in an enclosed space, the chemical residue left in the container builds up over time, damaging the stored article.

Bubble wrap, plastic sleeves, and newspaper all contain chemicals that can, over a period of years, cause items to deteriorate.

The American Institute for Conservation of Historic and Artistic Works (http://palimpsest.stanford.edu/aic) offers tips on how to protect and clean a variety of collectibles.