This is a three-part series exploring art restoration at Yale as the Yale University Art Gallery’s ongoing renovation provides increasing gallery space for the University’s more than 185,000 permanent collection pieces. Part 1 investigates the process of bringing art out of storage through the lens of the nineteenth-century Huntington murals. Part 2 probes the innovative techniques used and created by Yale conservators during the restoration of works like a fragmented sixth-century Byzantine mosaic found in the 1930s. Part 3 considers the art that conservation forgot.

Some art works are destined for decay.

While the Yale University Art Gallery conservation department is hard at work restoring pieces of the collection for a 2012 reinstallation in the renovated wings of the gallery, conservators say there are some art works that have damage that simply cannot be reversed because of the ways in which they were constructed.

Though the renovation will allow the gallery to showcase more of its 185,000-piece permanent collection, for some works, lack of floor space is not the issue keeping it off the gallery walls. Even if the gallery had infinite space to mount their collection, the most fragile works, such as a Syrian knitting sample dating from

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the third century, must be rotated off view every six to 12 months in order to slow its deterioration. But it is a deterioration that cannot be stopped, only slowed.

And ancient artifacts are not the only concern: 20th century works such as a plastic sculpture created in 1926 by Antoine Pevsner and given to the Art Gallery in 1941 are also at risk of ruin.

“[We] have a range of materials which are just intent on destroying themselves,” said Ian McClure, chief conservator at the Art Gallery.

While no artwork can be fully restored to the condition in which it left the artist’s studio, there are degrees to which a conservator can rehabilitate a work.

The challenge in conserving ancient textiles lies in the tendency for organic materials to break down with time; for modern art created from unconventional materials, unfamiliar chemical reactions pose a challenge to conservators.

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Antiquated textiles such as the Syrian knitting sample, which was found in the 1930s by Yale researchers, are sensitive to light and humidity and naturally degrade over time due to their composition, associate curator of ancient art Lisa Brody said. Some modern works made of more chemically reactive materials, though, break down at an even faster rate. For example, the cellulose nitrate that composes Pevsner’s plastic “Portrait of Marcel Duchamp” is highly self-destructive.

When contending with art works with continuing damage, conservators usually attempt to place the objects in storage or display units that eliminate degrading factors such as light, pests and chemical pollutants.

But the best way to slow the deterioration of an unusual work like the Pevsner sculpture is still unclear to the Art Gallery’s conservation team, McClure said. The degradation of the plastic happens from the inside out, beginning with internal fractures and ending with the art work crumbling to bits.

And the longer the conservators take to figure out a solution for this particular problem, the closer the piece gets to total destruction.

ORGANIC MATTERS

Generally speaking, objects constructed from organic materials — textiles, wood pieces, and paintings on paper — are most at risk of permanent damage, McClure said.

Though it is currently kept safe in the University’s Hamden storage facilities, the knitting sample, which was excavated from the Dura-Europos site in modern-day Syria, will soon go on view in the renovated wing of the Art Gallery, in a room devoted to the artifacts unearthed at the site. The collection also includes wool textiles and leather shoes, objects that would not have survived to the present day had they not been entombed in buildings buried in an earthen embankment constructed during a third century siege on the city.

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“Normally things like textiles, wood and leather don’t survive,” Brody said.

But the Dura-Europos artifacts did survive because they were buried in a dry, safe place underground that was left untouched for years. The conservators’ task now is to stay on top of the environmental factors such as light and humidity that were kept at bay before the pieces were excavated.

Indoor lights and ultraviolet rays are particularly dangerous because they fade textiles and sensitive paintings like watercolors. Conservators typically minimize these effects by manipulating the lighting the works are displayed under or rotating the pieces off-view.

“There are sensors and monitors that check the intensity of light,” Brody said. “You can sometimes lengthen [their time on view] by displaying them under dimmer light, or by putting them behind UV-protected glass.”

But light is not the only damaging factor to consider.

Conservators of organic objects often deal with pest control. The natural fibers of the Syrian knitting sample are of great culinary interest to insects, McClure said.

Art works must be stored in such a way that insects are kept at bay. Conservators monitor the gallery and storage facilities to ensure that no critters have nested among the art.

SELF-DESTRUCTING IN THREE … TWO …

While insects may be attracted to the gallery’s more digestible works, inedible 20th-century pieces have their own issues.

The “Portrait of Marcel Duchamp,” for one, has not aged gracefully.

“It’s totally green right now,” McClure said. “The cellulose nitrate develops all these tiny cracks inside, and then it goes completely opaque with cracks until pieces begin to drop off.”

For pieces like Pevsner’s sculpture, conservators can only hope to slow the pace of the object’s deterioration, as they cannot stop it entirely. The best way to accomplish this, McClure said, is still unclear.

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Yale’s conservators do know that only way to slow the sculpture’s degradation is to keep it refrigerated under very low temperatures, he said. But permanently keeping it in an enclosed space poses its own issues, as the plastic emits gases that contribute to its decline. To neutralize the effect, the conservation department has added carbon filters to the sculpture’s case to absorb pollutants in the air.

The gases arising from the Pevsner have the potential to corrupt nearby objects, McClure said, should it be displayed in open air. Certain metals like silver could tarnish if they are left in proximity to the plastic piece.

“That’s one reason to keep it enclosed,” McClure said. “To keep it away from other objects.”

These considerations make it nearly impossible to display the piece in the gallery with any regularity. The last time the sculpture was brought out of storage was for a special exhibition at the gallery last year called “Time Will Tell: Ethics and Choices in Conservation.”

‘THEY DON’T WANT THEIR PIECES TO SURVIVE’

Not only are certain art works difficult for conservators to preserve — some pieces are just not meant to last.

Modern-day conservators deal with the issue of contemporary artists constructing works from unconventional materials with intentional disregard for longevity.

“There’s definitely an element of the artist making something that’s ephemeral,” McClure said. “Sometimes artists say they don’t want their pieces to survive. And yet when museums collect things, [curators] want them to be preserved.”

The Museum of Modern Art’s collection, for instance, includes a dumbbell made of petroleum jelly, which begins breaking down at a single touch, McClure said. Digital installations such as videos also pose an issue to museums — with digital technology developing so rapidly, the equipment on which an installation is produced can quickly become obsolete. Institutions like the Museum of Modern Art often buy up equipment like video players to keep in storage, in case an installation breaks and cannot otherwise be repaired,

McClure said.

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And the breakdown of a piece is sometimes seen by artists as part of their artistic statements.

McClure said the conservation world broke out in debate over the preservation of wall drawings by Sol Lewitt, an American artist who wrote instructions for large-scale drawings that were then executed by others. Lewitt maintained that the artistic core of the project was not the object on the wall but his design, McClure said, and that if damaged, the drawing need not be restored. Still, some conservators felt that letting the drawings go unrestored would run against the core values of restoration.

“It was a very heated argument in the conservation press,” McClure said. “Some said that it should be restored, that letting it go is completely against the principles of conservation.”

When the renovated wings of the Art Gallery open in 2012, gallery-goers will see this debate in action, as pieces in various states of preservation are displayed alongside one another.

While Yale’s conservation department is employing innovative technologies to restore the gallery’s collection to a condition in which the wear and tear of time does not impede the viewer’s experience, sometimes the team has to settle for a less-than-perfect facelift.

As McClure said: “Conservation should be about finding equivalent materials so that it can look how it looked, rather than worrying about making it exactly the same.”