11/14/2012 09:42 am ET Updated Jan 14, 2013

Watercolors Can Be a Fragile Medium for Artists and Collectors

You can blame the artist who creates it, or the collector who puts it on display, but the real culprit is the watercolor painting itself. Watercolors just don't have long life spans in comparisons with oil paintings or sculpture. The colors fade, the paper rots or gets eaten by insects.

Over the long run, the collector is usually the one at fault -- as it is that person's responsibility to properly mat, frame, store and display the work. Still, artists can do a great deal to create pieces that are not likely to deteriorate soon after leaving the studio.

First, they can purchase and use the most durable, high-quality materials available. For instance, their paints should optimally be made of mineral pigments, which help their color longer (as they chemically inactive) than those created from vegetable dyes. However, mineral paints are not available in every color -- they tend to be darker earth tones -- and artists will likely have to use the more fugitive vegetable dyes.

Certain paint manufacturers, such as Windsor & Newton and Rembrandt, provide permanency ratings for their products, listing them as A (absolutely permanent), B (mostly permanent), C (utilitarian) and D (absolutely evanescent). An artist can also test the paints' durability by applying paint to paper, cutting the paper in half and putting one part in a southern exposure window for a few weeks or months and the other part in dark drawer. At the end of the test period, the degree of fading should be evident. Another aid to permanence is using the same brand of watercolors for any given piece, since manufacturers create their own chemical balances which vary from one company to another.

No less important than the paint is the paper, which is made from wood pulp, cotton, linen or some combination of these. Just as with paints, paper should be tested, using the window-and-drawer method, or even baked in an oven to artifically age it.

Another simple test is to run a wet brush over a piece of paper to see how much it buckles. A very heavy paper won't react to changes in the environment as much as lighter paper. Using heavy paper -- 140 pounds and up -- makes sense when painting with a very thick watercolor, which tends to crack with the movement of the paper. Heavy paper is also good when the work is moved a lot. The main signs of trouble with an artist's paper are discoloration or overall darkening as well as embrittlement, which are often the result of acids in the paper breaking down the cellulose polymers that hold the paper fibers together and make them flexible.

The are various ways in which acidity becomes a part of, or can attack, paper. Unrefined wood pulp is high in acidity and will cause yellowing in a short period of time (most newspapers are 80 percent unrefined wood pulp). Other internal problems that may damage the paper are chlorine from the bleach that wasn't completely rinsed out of the paper when it was washed, sizing agents (used to give paper its absorbency and surface character) that leave behind metallics (that rust) or organic particles (that form fungus) and brighteners (that make the paper look very white) that may also leave chemical compounds behind.

Air pollution (acidic gases) is another cause of paper deterioration, as is contact with poor quality framing and matting materials (acids in these discolor the paper where they come into contact). Of course, spills of coffee, oil, tea or water may also lead to deterioraton and staining. It is advisable for artists to maintain a clean workplace, and for collectors to protect pieces from young children or their own clumsiness.

Artists should store their paper in a dark, acid-free environment; they should never leave their paper outdoors. There are instances of artists buying very good paper but, by the time they're ready to use it, the paper is discolored from having absorbed too many acids from the environment.

Another way artists inadvertently damage their own paper is by soaking it in tap water -- a traditional technique that makes the paper more flexible so that it can be taped down on a drawing board -- instead of distilled water. The water should also be changed daily. Water from a household tap may contain acidic minerals that will stain the paper or cause fungus. The same is true for water used to moisten the colors on the artist's palate or for a sponge that is used to keep the paper or the brush wet.

Another problem affecting all works on paper is insects and rodents which like to eat it. As insecticides may damage the paper, conservators generally advise collectors to store works on paper away from places these pests can gain access to.

The remaining problems that may affect watercolors -- overexposure, poor quality matting and framing, heat, light and humidity -- are often more applicable to collectors than to artists, but they still are important concerns for watercolorists who frame and display their own work. In addition, artists may want to advise collectors on proper handling techniques.

Then there is the problem of living with art. The artwork needs to be placed in a dimly lit room. That means, close the shades or drapes in the morning or when you take a vacation. That means, rotate the work from an outside to an inside room every so often. Ideally, the work should not be on display any more than three months a year -- that's what museums do -- but, if you don't plan to take the work down periodically, the room shouldn't be flooded with a lot of bright light.

Daylight is the major scourge of art, emitting damaging ultraviolet rays, but fluorescent lights also give off ultraviolet rays. Regular light bulbs, or incandescent light, are the least harmful as they largely emit heat that is easily diffused in a room.

Galleries in museums devoted to works on paper are usually lit to scientific measures of between five and eight "foot candles." To determine whether one's own rooms are brighter than that, one can use a photographic meter, which many professional photographers use. Setting the ASA scale to 100 and the f-stop at 5.6, the indicated shutter speed will be equal to the number of foot candles. If that number exceeds eight, the room should be dimmed or the artwork moved elsewhere.

In addition, room temperature should be maintained between 60 and 75 degrees Farenheit and the relative humidity (which can be measured with a hygrometer, a device carried by certain hardware stores and costing as little as $25) between 45 and 55 percent. In that humidity range, mold cannot survive.

All mats and backing, which provide physical support to the work, should be acid-free. Cotton rag board, buffered rag board or conservation board are all terms for these cardboard supports that are pH-neutral or slightly alkaline in order to protect the watercolor from external acidity. A wood pulp mat, on the other hand, would damage the paper.

The backing itself should be thick, to protect against accidental puncture, while the matting (an internal frame, composed of cardboard with a carved-out center) should be deep enough to provide a layer of air between the work itself and the glass on the frame. Condensation on the glass may result in mold growth if the paper and glass touch (and adhere), and that touching may take place if the paper buckles due to changes in humidity, even when the work is correctly matted. To prevent this from happening, conservators often suggest double matting the picture to increase the space between the paper and the glass. They also recommend that glass be an acrylic plexiglas, which reduces harmful ultraviolet rays.

Various companies around the country produce archival, or tested acid-free, materials and will supply catalogues of what they offer. A local museum conservator can recommend the name and address of those which he or she worked with.

Conservators would not have their hands so filled with art requiring extensive repair if artists used archival materials to begin with. Franz Kline, for instance, painted on the Yellow Pages, while Jackson Pollock occasionally used shirt cardboard. They probably did not expect these pictures to last for the ages, but collectors, who spend large amounts of money for works by these artists, do. It behooves both the artist and the collector, therefore, to proceed with greater care.