In the early 1960s, curators at the Philadelphia Museum of Art noticed something funny about one of their modern-art sculptures: It smelled like vinegar. Worse, the once-clear plastic sculpture had begun browning like an apple, and cracks had appeared on its surface. By 1967, Naum Gabo's translucent, airy Construction in Space: Two Cones looked like Tupperware that had gone through the dishwasher too often.
The volatile Gabo got so angry at the curators (he blamed the deterioration on their keeping his work in an airtight display case) that he took the sculpture back to repair it. That didn't work—things, in fact, got worse—and he finally gave up. He cast a replica of Two Cones, donated it to the Tate in London, and gave Philly back the degraded original.
The incident would have remained a footnote in art history, except that other Gabo pieces (including the Tate's replica) started falling apart, too, and in much the same way. They flaked into pieces, turned strange colors, and began to reek. Gabo found a reason to blame other owners for mishandling his work, but curators soon discovered a common factor: rhodoid, an early plastic made of cellulose acetate.
In the 1920s, Gabo and other artists began experimenting with plastic, both because it offered the freedom to create any shape in any color and because they believed artists should embrace technology and a plastics-based industrial future. (Gabo was trained as an engineer.) Plastics manufacturers assured the artists that cellulose acetate was durable—Greek marble for a new generation. Not quite. It turned out plastics were no more intrinsically stable (and sometimes less stable) than wood, paint, or any other media—a detail Gabo and the Philadelphia curators never suspected until too late.
The problem of preserving plastics isn't limited to highbrow art. Not long after The Graduate debuted, manufacturers around the world began to incorporate synthetic polymers into their goods. As plastics revolutionized the making of furniture, toys, health care products, and electronics, museums of industry, design, and medicine began snapping up plastic objects that were either historic (the first artificial heart) or culturally important (Barbie dolls). Plastics hold up well for the decade or so during which a consumer uses most products. But museums, unlike consumers, are in it for the long haul, and when plastics crash, they crash precipitously. As a result, museums of all sorts have been having Gabo moments in the past decade.
The casualty list is appalling: Antique plastic dolls at the National Museum of Denmark have begun to peel and flake; classic furniture at the Victoria & Albert Museum in London might as well have been left out in the sun for years; the first-ever plastic toothbrush, at the Smithsonian, is collapsing into a pile of crumbs; etc. A whole generation of irreplaceable items that are as representative of our culture as pottery or flintheads were of ancient ones are dying—and many people charged with their care have no idea how to stop further damage.
A handful of unstable, "malignant" plastics are responsible for most of the carnage. Cellulose nitrate was the first widely used plastic (it dates to the early 1830s); it was used to make the film in reel-to-reels. It's remembered today for being a notorious fire hazard: Billiard balls made of cellulose nitrate would occasionally explode on contact, and the plastic was responsible for the destruction of many early movie theaters, as hot projection booths caused the film to catch fire. For safety reasons, cellulose acetate, the material Gabo used, began to replace cellulose nitrate in many applications in the 1930s, though it wasn't any more durable. Because both plastics were based on readily available plant matter (cellulose is the main component of a plant's cell walls), they found widespread use until the 1970s, despite their flaws.
More recently, manufacturers and artists have turned to latex and wholly synthetic plastics like PVC or polyurethane. But these plastics have also proved feeble over the long term. At a molecular level, plastics are long chains of a single molecule repeated over and over. Such long chains would be uselessly brittle on their own, but chemists realized they could add chemicals, called "plasticizers," whose molecules work their way between the chains and soften the plastics up. This greatly increased malleability, and virtually all plastics today employ plasticizers. Unfortunately, plastics will squeeze the plasticizers out over time. This process pushes the chemicals to the surface of the object, leaving the underlying plastic fragile. Different plastics deteriorate in different ways under different conditions, depending on what plasticizers or dyes were added. But the end result tends to be forms of matter rarely seen outside the reject piles of industrial chemistry labs. You can recognize "bleeding" or "weeping" plastics by the slimy plasticizers pooling on their surfaces. Other plastics push powder to their surfaces and feel sugary to the touch.
Scientists have struggled to figure out the best general strategy for the long-term care of plastic objects. One necessary step is keeping them out of sunlight, since ultraviolet light breaks down both plastic fibers and the colored pigments in plastics, bleaching them. Curators also need to watch out for biological agents. Molds and bacteria have evolved to eat plastics, and although it's not their preferred food, some beetles will eat through Plexiglas if hungry enough.
It's inevitable, however, that even plastic objects kept in dark, sterile drawers will begin to deteriorate chemically. The wholesale dilapidation of something like Gabo's Two Cones usually takes a few decades. More durable plastics can last longer, but even they are slowly crumbling.
Often the only clue a plastic is degrading is its odor. Some begin to smell like ammonia or take on a sickly new-car smell. PVC weeps chlorine, giving it a swimming-pool smell, and any plastics with acetate eventually give off whiffs of acetic acid, which is found in vinegar. Other plastics are redolent of burnt milk, burnt hair, celery, cinnamon, raspberry jam, or camphor "muscle rub."
Worst of all, when plastics weep and bleed they can corrupt everything around them. Chemicals evaporate from their surface and acidify any moisture inside a display case. This causes mini bouts of acid rain that in turn eat away at the plastic in nearby objects—as well as any cloth, metal, or paper in those objects. Curators can lay down special carbon cloths beneath a plastic object to absorb some acid, but some plastics have to be quarantined immediately. Museums have also used plastics to coat nonplastic objects like silver (to prevent tarnishing) and paintings (to prevent flaking). But plastic coatings often "bloom" and turn opaque or "crizzle" (i.e., wrinkle) like dried rubber cement, changes that can damage the very object the coating was meant to preserve.
As of today, most chemical damage to plastics is irreversible, and conservators focus less on rehabilitation than simple maintenance. The Smithsonian Air and Space Museum recently asked the Museum Conservation Institute to help preserve a high-altitude flight suit in its collection. The suit had belonged to the one-eyed aviation pioneer Wiley Post. The leather straps and cotton garments in Post's suit look fine, if a little dingy. But his plastic gloves look like the shriveled hand of a mummy. Conservation scientists said even light handling of the gloves would cause them to crack and crumble, and they admitted they can do little but put the suit in deep-freeze storage and take pictures for posterity.
One branch of the art industry that has taken a particular interest in the question of how to preserve plastics is insurers, since they will have to pick up the tab for damaged goods. Insurance agencies fund much of the research into preserving plastic art, a fledgling science aching for a breakthrough. One company, AXA Art Insurance, publishes a book with the dour title Plastic Art: A Precarious Success Story, and has held numerous training sessions to teach curators the best-known methods of staving off decay (and, it hopes, to generate new ideas on how to reverse it). In a warning to museums snapping up the work of some of today's hottest artists, the AXA book states that plastic-heavy pieces by Damien Hirst, Matthew Barney, and Jeff Koons will be "difficult, costly, and nerve-racking to preserve."
In the future, museums will probably have to be stingier about sharing or even displaying plastic holdings. Conservators at New York's MoMA say it frequently gets requests to loan out Eva Hesse works, such as Viniculum II, which consists of latex pieces affixed to a wire, but they have to refuse because of their fragility. In even worse shape are the plastic sculptures of blue-collar workers, overweight shoppers, and white-trash tourists by Duane Hanson, a name on the lips of most every plastics curator. His grotesque renderings used to startle museum-goers with their uncanny realism, but as the sculptures peel and crack, they're looking creepy for different reasons. When a Hanson statue, Woman With Handbag, began to decay at the Wallraf-Richartz Museum in Cologne, Germany, curators cleverly asked the artist to "age" the woman by playing up her age spots and changing her hair. But since Hanson's death in 1996, the museum has limited the time it shows the piece.
A few conservation scientists worry even more about the next generation of plastics—biodegradable plastics, which are supposed tobreak down. Artists are not always a read-the-instructions bunch, and conservators fear they will ignore manufacturers' directions about the lifetime and durability of "green" plastic and use it anyway. Brenda Keneghan, a conservator of modern materials at the Victoria & Albert Museum in London, summed up her fears about the future of plastics in art this way: "Everyone else in the world is trying to get rid of them," she sighed, "and we're trying to preserve them."