Dust on your artwork? Don't reach for the vacuum cleaner

If everyone lived in museums, preserving works of art wouldn't be a problem. But people like to open their windows in the spring and fall, close them and turn on the heater in the winter or the air-conditioner in the summer, alternately drying and humidifying the air, dramatically raising and lowering the indoor temperature. This can be murder on art, which needs a stabilized environment -- but how else are people to live? Knowing how to live with valuable objects is as important as knowing what to collect. Many people make mistakes that ruin their possessions because they thought they knew what they were doing; others allow damage to take place by doing nothing.

There are some easy, practical ways to avoid problems. Pictures should be kept at a reasonable distance from doors and windows, and humidifiers are advisable when air-conditioning or heat is on. Art should not be hung above a fireplace -- which naturally draws in dirt and dust -- nor on an exterior wall of a house, as the cool air of the outside and the warmer air inside may produce some condensation on the art itself.

Many people believe that they are showing off their paintings by putting them in frames to which lights in brass holders are attached. But the heat of the light works to quickly fade the colors and burn the work.

Others have been known to take a vacuum cleaner to a canvas in order to remove dust, but the suction of the machine is usually too strong and pulls bits of paint along with loose dirt off the picture. It also frequently leaves an indentation in the canvas, which is why most art conservators recommend feather dusters for the job.

Aside from dusting, it's better to entrust the cleaning of your artwork to a professional, rather than to attempt it yourself. There isn't much an amateur can do that won't cause damage, but there are a lot of things one can do that will cause damage.

Soap and water, for instance, are a no-no. Soap comes in a concentrated form and can damage the paint as well as diminish the luster of the colors. The water, too, will penetrate to the canvas through the cracks in the paint, making the canvas expand and contract as it dries, resulting in a loosening of the bond between the paint and the canvas which often causes the paint to just flake off.

Perry Huston, a private art conservator in Fort Worth, Texas, notes that one prevalent old wives' tale says that one can clean an oil painting or art print with white bread, as well as a split-open potato, garlic, or onion. There's logic in this, though faulty, he says. ``These foods have the right amount of moisture content to pick up water-soluble dirt without getting the picture wet. However, they also contain bacteria which may be left behind on the artwork,'' and this begins to eat away at either the paint or the paper.

Other do-it-yourselfers are acquainted with some of the chemical solvents used in cleaning works but are not knowledgeable about the correct proportions. Alcohol and bicarbonate of soda, for instance, have long been used by conservators, but indiscriminate use or overly broad application of these may dramatically harm any work.

Some of these people use solvents which the art conservation field has stopped using, such as benzene and carbon tetrachloride, which are known carcinogens, or caustic soda -- otherwise known as lye, the main ingredient in Drano and various oven cleaners. Barbara Heller, head of painting conservation at the Detroit Institute of Art, notes that caustic soda is very good at eating through dirt and old varnish, ``but it also eats through everything else, including the paint and the canvas. It creates a big hole. You just can't stop it.''

Art conservation does not lend itself to quick and easy solutions. It is, instead, a slow, painstaking matter of cleaning small areas of a work at a time, understanding that each color in a painting has a different solubility. A cleansing agent may work well on one color but completely destroy another and, because of this, conservators never work on the surface of a work with any tool whose head is larger than a cotton swab.