New tech saves old books

Somewhere within the vast underbelly of Sterling Memorial Library, a cart of decaying books is wheeled through a windowless corridor. Depending on their states of deterioration, these volumes may be reconstructed, scanned or washed in alkaline baths in an attempt to preserve the information held within their pages.

Though the idea of cutting-edge science may seem at odds with a building modeled after a Gothic cathedral, Sterling’s Preservation Department applies high-tech processes on a daily basis to ensure that future generations will have access to Yale’s vast collections.

An example of an ambrotype, an early type of photography. One ongoing preservation project involves building a case to protect the images.
James Smithy
An example of an ambrotype, an early type of photography. One ongoing preservation project involves building a case to protect the images.

“We basically work at the marriage of chemistry and art,” said Tara Kennedy, a preservation field services librarian.

The department, founded in 1973, is the oldest of its kind in the United States, Kennedy said. Yale’s preservation department is divided into four subcategories, each with its own specialty: the administration and field service unit; Reformatting and Media Preservation (RaMP), which primarily works to move information from obsolete media to more current technologies; Collection Conservation, which deals with repair and maintenance of circulating materials; and the special collections Conservation Lab.

In the Reformatting and Media Preservation department, located in Sterling’s basement, the preservation staff emphasizes the rescue of information over the value of objects as artifacts. They work on books, periodicals, and audio and video recordings. Frequently, decaying books that end up at RaMP are discarded in favor of reprinted or digitally scanned copies produced by outside agencies, and RaMP’s primary role is the coordination of these various reformatting services. RaMP also focuses on phasing out obsolete media, such as eight-track cassettes, pneumatic video cassettes and 16-millimeter film, said David Walls, a preservation librarian within the department. As Yale’s Music Library houses some of the earliest recorded sounds, this objective is particularly pressing.

“We scan and copy the material to a current format,” Walls said. “We want to make sure the information survives, no matter what it’s on.”

For example, RaMP is currently working with the News to make digital images of all its past issues, providing a searchable database that will include advertisements and original page layouts, Walls said.

The most common problem faced by RaMP is the increasing brittleness of paper pages over the years. Once-flexible chains of cellulose, the primary component of plant matter, make up the paper that most books are printed on. Over the years, these polymers are attacked by acid hydrolysis, resulting in shorter cellulose chains and more easily damaged paper. Books printed before 1850 used materials with longer and more durable cellulose chains, such as linen and cotton. But around the time of the Civil War, most publishers shifted to more affordable wood pulp, which has shorter, more easily degraded molecules. These books frequently end up as cracking, flaky texts that need to be reprinted and rebound.

Though printers have generally turned to less acidic and more durable materials, Yale still acquires many books from the developing world, where printing techniques are less developed. To prevent the degradation of these materials, books are treated in an alkaline bath in a process known as mass deacidization.

“We recognize we’re buying a lot of books on acidic paper,” Walls said. “These books are chemically treated with medical-grade stomach antacid, like magnesium oxide.”

Yet another threat facing printed materials is light, which also causes the breakdown of paper’s cellulose chains. High-frequency ultraviolet light is the most damaging to paper, though wavelengths all the way down to infrared can still be potentially damaging, Kennedy said. Particularly susceptible to light are high-lignin papers such as newspaper.

In the adjacent Collections Care Department, conservators work to maintain the physical books in Sterling’s circulating collection. The tasks in the Collections Care department range from constructing new bindings and covers to giving books new spines. If an item has particular value as an artifact, the staff will construct boxes to protect it. Depending on the task at hand, the department uses two different adhesives — a wheat-based starch glue or a polyvinyl acetate — in making repairs on books. Wheat starch is removable with deionized water, so it is frequently used on the more delicate parts of the book, such as the interior pages. The polyvinyl acetate, on the other hand, is typically used on the outer casing of the book for more durable and permanent results.

Books that suffer student-inflicted damage are sent to Collections Care, and department head Ian Bogus said the most commonly seen damage is cockling, or “wavy book syndrome,” which usually manifests itself after the book has been exposed to water. Occasionally, this damage is also associated with the growth of mold spores. If mold appears, the standard protocol is to lower the book’s temperature, and then vacuum off the mold spores with a HEPA-approved vacuum under a fume hood. Sterling’s stacks maintain low temperatures and humidity, so the chance of a mold problem developing within the library is very low, conservators said.

“Most moldy materials come from students’ backpacks, not the stacks,” Bogus said. “It’s a very stable environment.”

A few flights upstairs, nestled in the stacks on floor 1MB, the Conservation Lab works to preserve rare materials from Yale’s special collections. In effect, it is the VIP section of the library’s preservation efforts. It mainly treats items from the Beinecke Rare Books and Manuscripts Library, though conservators try to accommodate pieces from other collections as well. Here, the artifactual value of pieces is at a premium as many of the items treated here have immense curatorial value.

“We try to save as much of the original material as we can,” said Paula Zyats, assistant chief conservator. “It’s more about the aesthetics, so we really rely on what the curators need.”

Many of the processes used in the Conservation Lab are refinements of those used in the RaMP and Collections Care Departments. For instance, a similar system of deacidization is used, though on a smaller scale. In the Conservation Lab, books are treated individually with an aqueous solution of calcium hydroxide; the pH is slowly raised to 8 or 8.5 in order to deacidify the paper as well as to provide a buffer that will protect it in the future, said Zyats.

Yesterday, paper conservator Marie-France Lemay was working on a series of early ambrotypes acquired by the Beinecke in the 1990s. The ambrotype, popular in the 1850s, lacks the daguerreotype’s shiny quality while sharing its fragility. Many ambrotypes are housed in folding cases to protect the images. But the series Lemay was working on lacked those protective casings, and she was working to construct new cardboard containers to house the images.

Lemay’s bench, the fluorescent light and the occasional white coat are reminiscent of a lab in Kline Biology Tower. On a table beside the window, an English dyer’s book from 1768 rests below a distinctly 21st century fume hood. Nearby, a conservator wields a delicate set of forceps, dissecting a yellowed tome from the Divinity School. This room exists on the boundary between two distinct disciplines, and never is it more apparent than when one steps from its stark tiled floor into the darkened stacks. A few steps later, walking through the Gothic nave of Sterling proper, one could not feel more removed from the lab. The unassuming display case by the exit, filled with old-looking volumes, serves as the only quiet reminder of the preservation department’s critical role.

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