My husband and I have just moved into a home here in Naples. We haven’t yet agreed on where to hang a painting and we have it, along with all of our memorabilia, genealogy records, cut-glass collection, and past tax records, in our garage. We aren’t used to not having basements, attics, or large closets and now we can't even get our cars in the garage! Is the painting, an oil on canvas, we bought in Paris, okay in the garage?
Stored in the Garage
Welcome to Naples. You may have noticed that along with our sunshine and Gulf breezes, we have hot, humid days and afternoon thunderstorms during the summer wet season. As they say, “it’s not the heat, it’s the humidity”. And it’s the humidity, even more than the heat that causes issues for artwork. Relative Humidity (RH) is a measure of the amount of moisture in the air relative to the amount the air is capable of holding. RH is usually reported as a percentage.
Temperature can affect the RH and changes in temperature, causing changes in RH is the greatest concern. Sharp changes in temperature and humidity will cause swelling and contraction of materials. Since a work of art is composed of different materials such as the canvas, the oil in the paint, the pigment, the metal frame, and the wood stretcher, each of these materials will swell and contract at a different rate. It is this expanding and contracting that causes damage to the painting.
High humidity (of RH 70% or more) can cause mold and fungi to grow on the canvas of your painting. Effects of humidity can come in physical changes such as: warping, disjointing, splitting, fiber breakdown, delamination, and cracking; and chemical changes such as corrosion of metals, fading of dyes, clouding of glass, crystallization, disintegration and yellowing of paper.
It is best to store paintings, as well as other important or fine papers, textiles, glass, and furniture in a controlled environment with a RH of 45 -55% and a temperature of 68 to 72 degrees Fahrenheit. It is best not to have the temperature vary much during a 24 hour period and your garage is not protected from the changes in temperature during the day and night.
Your books and papers in your memorabilia, genealogy, and taxes are absorbing moisture in your garage and likely growing mold. You may notice small brownish dots have appeared on the paper, this is called “foxing” and is a result of mold growth.
Your canvas painting is expanding to absorb the moisture and it will do so at a different rate than the wood stretcher will resulting in the canvas “sagging”. The sagging may also cause the paint to crack and flake off the canvas.
It is best to store your painting, and other important items, in a cool, dry place. We recommend you buy or rent an indoor, air conditioned storage unit at a warehouse convenient for you.