Before investing in a work of art, experienced collectors tend to question its condition: Might this sketch be torn or creased underneath its frame? Has that oil on canvas been over-cleaned? Whether a smart acquisition stays in good shape, however, depends not only on how it is handled, displayed and stored, but also on the chemical composition of the materials from which it was made. If that sounds like an academic point, consider the works of Albert Pinkham Ryder (1847–1917). The eccentric American artist purportedly incorporated such unorthodox materials as sand, sugar, tobacco juice and urine into his paintings. “The result has been a nightmare for conservators,” says Naples, Florida, appraiser David C. Eldridge. “Some of his paintings have turned absolutely black. They are shadows of their original selves.”

Or take the case of the melting plastic sculpture. After the mid-century piece mysteriously began to collapse and drip at one end, its owner turned to the Chicago Conservation Center for answers. “The polymer that was used was a new material at the time,” recalls Megan Ann Jones, vice

Lou Cabeen, "Labor: Desire," 1994, art quilt created  from annotated, but now-fading, receipts.

president of client services for the private conservation lab. “As the plastic aged it was starting to, as was described by the specialists we contacted, ‘spontaneously de-polymerize.’” When considering an acquisition, those who regard art as a long-term investment should learn as much as possible about the durability of the materials used, Jones notes. Every category has its own red flags-unstable substances that give conservators and appraisers pause. Of course, some works pose more obvious problems than others. “We had one piece that was made with food products,” Jones says. “It had water damage and the food had completely disintegrated—they were croissants.”

Mixed Media
Contemporary artists recognize few limits when it comes to the diversity of materials they will affix to canvas or panel. German painter Anselm Kiefer uses material like straw or dried flowers, American painter Julian Schnabel gained notoriety for composing with broken plates and British artist Damien Hirst outraged animal lovers by incorporating butterfly wings into his paintings. So far, the possibility of conservation problems has done nothing to reduce the value of these works, notes Nan Chisholm, a New York art consultant and appraiser. Nonetheless, collectors should be clear about the future problems such a jumble of elements can create, says St. Simons Island, Georgia, appraiser Judith Ellington. “Mixed media can be particularly troublesome, because often all the elements that go into the composition are either not known or have different levels of longevity or care,” she says. “I have a painting that is primarily oil on canvas, but it also includes a section from the stock reports page of the Wall Street Journal. These elements are not going to survive at the same rate.”

Traditional paintings
Even when the composition includes no shattered crockery, stale croissants or dismembered insects, conservation challenges may loom. Conservators and appraisers who work with traditional oils on canvas, for example, know to watch out for varnishes, grounds and supports that can undermine otherwise-pristine paintings. Some of these potential problems are visible to the naked eye; others require laboratory tests. “A natural resin varnish that has yellowed with age, we can take that off and bring it back again with a fresh coat and everything will be fine,” Jones says. “But an 
oil-based varnish layer that is yellow or dark is extremely difficult to remove because it requires materials-different types of solvents-that are so strong they can threaten the paint layers beneath. If a painting is clear but actually was shellacked two weeks ago, then when that darkens 10 years down the line nobody will be able to do anything with it.”

If the varnish on top of a painting is critical, so, too, is the support upon which the work rests, adds Chicago-based art dealer and appraiser Thomas de Doncker. Artists began using Masonite in the 1920s, for example, because it seemed to share some of the same properties as the hardy oak panels favored by 17th-century Dutch Old Masters. The passage of time, however, has caused some in the art world to think twice about manmade wood products. Formaldehyde resins sometimes used in their manufacture can produce gases that bubble to the surface and damage pigments, de Doncker says. Masonite also swells when exposed to water, not unlike a paperback dropped in a bathtub. Experimentation with such materials has by no means been limited to starving artists: Even Picasso painted on plywood.

Works on Paper
The chemicals used in the manufacture of another wood product—paper—also can be critical to its conservation. Much to the irritation of later generations of collectors, the printing industry in the mid-19th century moved from low-acidity paper made from rags to high-acidity paper made from wood pulp. “It is unfortunate,” Eldridge says. “Entire collections from post-1850 are rotting. You can open up a volume from 1820 or 1830 and it is really nice. But open one from 1860 or 1880, where the wood pulp and the oxygen have interacted, and it will have gotten very brittle.” Acid-based paper can be treated—but only at great expense. The cost of restoration, Eldridge notes, can exceed the value of the work itself.

Transitory by Design
Asking pointed questions about the materials used in a work of art can help collectors avoid problematic pieces. There may be a downside, however, in focusing too heavily on permanence. For one, the task ultimately may be futile. “From the moment a piece is made it essentially is beginning to degrade,” says Margaret A. Little, objects conservator at the Winterthur Museum & Country Estate in Winterthur, Delaware. “It is just a part of the natural lifecycle of different materials.” For another, works that make use of experimental mediums are all but a given in contemporary art; collectors who avoid them risk missing out on rewarding aesthetic experiences. “Not only does contemporary art challenge what our definition of art is, it challenges what our definition of restoration is,” says MoMA Chief Conservator James Coddington. “That is one of the things that is so vital about it—it is perpetually challenging.”

Indeed, the poignancy and meaning of a work may derive in part from its very impermanence, says art-quit collector John M. Walsh III. For example, among the cherished works in Walsh’s New Jersey home is “Labor: Desire”—a quilt made of paper store receipts inscribed with Seattle artist Lou Cabeen’s handwritten commentaries. “The ink is deteriorating over time and will gradually bleach out until nothing much is there,” Walsh says. “The object itself is transitory. You have to enjoy it as it exists.”

That understanding, in the end, may be the key to fully appreciating any art collection.

For More Information
Chicago Conservation Center Inc. (800) 250-6919.www.chicagoconservation.com
Nan Chisholm Fine Art Ltd., New York. (212) 861-2720.
Thomas de Doncker Fine Arts, Chicago. (312) 421-8809. www.tddfa.com
Eldridge Appraisals Inc., Naples, Fla. (239) 598-2225.
Ellington Art Appraisal Services, St. Simons Island, Ga. (912) 638-4515.
Winterthur Museum & Country Estate, Winterthur, Del. (800) 448-3883. www.winterthur.org.

Joel Groover is a former Art & Antiques Senior Editor.