Collections Care 101 - Environment

A lot of people collect something. Coins and stamps have been popular for over a century, souvenir plates and spoons for decades, and I’ll bet there are still big collections of Beanie Babies to be found out there. Collections can be as diverse as collectors, but they all have one thing pretty much in common—most collections suffer damage from same environmental sources. Today I’m discussing three common factors that will damage most collections, whether they’re in the British Museum, or in your living room—and what you can do to minimize them.

Light
Thanks to sunscreen and sunglasses commercials, a lot of people know that Ultraviolet (U/V) light is bad. And it is—it’s the most damaging component of the light we normally encounter. U/V waves can cause fading and weakening of molecular bonds, leading to cracking—even total disintegration in some cases. Natural sunlight and fluorescent bulbs emit a lot of U/V—best not to let either of these shine directly on your collectables. If that can’t be avoided, you might want to look into U/V filters for your windows and light fixtures.

Remember U/V isn't the only harmful component of light. Visible light will also contribute to fading/yellowing and embrittlement, and all light damage is cumulative and irreversible. For maximum preservation, keep the room dark as possible whenever you're not there to enjoy your collection.

Relative Humidity
With Relative Humidity (RH), too dry can be just as bad as too humid. Below 35% RH, organic materials (such as fur, leather, pulp paper, etc.) become increasingly brittle. As RH increases, fibres in wood, fabric, paper, etc. swell as they absorb moisture from the air. As RH decreases, the fibres shrink as they dry out. If this swelling or shrinking happens too quickly, the fibres will break and weaken the object. So, the key to managing Relative Humidity is to keep it stable (ideally, less than 5% fluctuation per day), and in a range between 35% (below which things start to get brittle) and 65% (above which mould growth can occur).

Temperature
Temperature itself isn’t as crucial as RH. However, there is a direct inverse relationship between temperature and RH (that is, as temperature drops, RH increases), so temperature should be kept stable as well. Lower temperature is better than higher, since chemical reactions and biological activity (like mould, or insects—both of which can eat most organic materials) both slow down in cooler temperatures. Just as long as it's not so cool that you need to turn the thermostat up whenever you're in to view your collection! In the Museum, we keep our storage temperatures at 20ºC, because that’s most comfortable for the people who work with the collections.

Generally, basements (as long as they’re dry and not susceptible to flooding) are good places in the home for collectibles—the temperatures tend to be cooler and more stable, and they’re usually naturally darker. If you’re really concerned about environmental damage, you might consider collecting glassware, glazed ceramics, or rocks—all of which are pretty much resistant to the effects of household light, humidity and temperature.