A Meditation on Preservation
By Charles Buchanan
In the face of 500 years of change, one face has remained the same. Leonardo da Vinci’s drawing of the Angel for the “Madonna of the Rocks” still looks as youthful and fresh as the day she was sketched, her alluring gaze free of crease or blemish.
The angel owes her clear complexion to progress in preservation, a specialty that blends art and science in a manner that would impress Leonardo himself. And while preservation was once the province of curators and archivists alone, today it is a crucial facet of many fields, including research, health care, and information management. An increasingly digitized society requires that agelessness extend to patient records, spreadsheets, and family photos, along with humankind’s greatest masterworks.
Preservation, at its core, is about time travel. It allowed Leonardo’s Angel to cross an ocean—and the gulf of centuries—to visit Alabama last fall, when the Birmingham Museum of Art organized an exhibit of 14 of his drawings—along with his legendary Codex on the Flight of Birds. It was the first time that the drawings, from the Biblioteca Reale in Turin, had been shown as a group outside Italy.
But how can ink and chalk on paper—not to mention paintings, documents, and books—outlast things made of much stronger stuff, from buildings to empires?
Immortality, it seems, begins with quality. “Certain materials have certain time limits,” says UAB archivist Tim Pennycuff. Leonardo’s inks, chalks, and paint pigments have lasted because they were made from stones and other natural materials. For drawings and documents, the type of paper used is especially important. Leonardo’s paper was made from natural fibers, which helped preserve his works, explains UAB art historian Katherine McIver, Ph.D.
Changes in the paper production process, including the addition of bleaches and other chemicals, have taken a toll on works from later eras. “Books from the late 19th century are falling apart because they started using wood pulp, which is very acidic,” says Pennycuff. “Books from before the Civil War and most modern books use a different paper process, so they last longer."
Whatever the medium used, the greatest threats to art and literature over time aren’t caustic reviews, but light and humidity. “If you go into a gallery, and it takes your eyes a minute to adjust because it seems like the light level is low, that’s probably about right,” says Brett Levine, curator of the UAB Visual Arts Gallery. Bright light—especially ultraviolet light—can cause mediums like ink and watercolor to fade; most exhibit spaces add filters to their bulbs to block ultraviolet light, Levine says. “Museums also understand that they have to rest a work of art—usually three times longer than it has been on display—which helps the residual effects of long-term light exposure to dissipate.”
As for humidity, “if your environment is too dry, works on paper will crack; if it’s too moist, they will mold,” says Levine. He explains that paper, which is made from natural components, sets its own equilibrium to its environment. “If you see a work on paper that looks wavy, there’s too much moisture in the air. The natural fibers in the paper are absorbing the moisture. If you remove the humidity, it will flatten out over time.” Because humidity and temperature are closely related, most museums maintain a temperature between 65 and 75 degrees, with a humidity range of 45 to 55 percent.
Even simple oxygen can create havoc, causing inks and paint pigments to fade, for example. “But if you encase a work in a glass container and replace the oxygen in the container with argon gas, it can’t deteriorate,” Levine says, citing the Declaration of Independence at the National Archives in Washington, D.C., as an example. Argon is an inert gas, Levine explains, meaning that it does not cause chemical reactions.
Museums and archives must be on guard against light, heat, humidity, and chemical reactions “24 hours a day, seven days a week, 365 days a year,” adds Pennycuff, and they go to great lengths to maintain their strict standards. In addition to meters placed in each exhibition gallery to measure temperature and humidity, many museums install special heating/air-conditioning systems and even extra generators to ensure a constant environment in case the power fails. Their storage systems, from boxes to racks to cabinets, are specifically constructed to be free of acids and volatile organic compounds.
Caring for art and artifacts that travel, such as the Leonardo drawings, can present a major challenge, since they must never leave a climate-controlled environment. “If you ship me a painting,” Levine says, “the first thing I do is put it in a secure, climate-controlled space, and I don’t open the crate. I want it to acclimatize because I don’t know how sealed the crate is; I don’t know how hot or cold it was in the truck. I let it sit there for a day so that it’s regulated in temperature and humidity. And once you’ve got it in that controlled environment, it must stay in that environment from door to wall to storage.” Levine adds that most galleries rely on companies that specialize in shipping art in controlled environments, either by truck or plane, to move their works around the world.
Restoration vs. ConservationOver the centuries, Renaissance artists such as Leonardo da Vinci have had a little help in keeping their paintings vibrant and colorful. “You want a work of art to look fresh and new, so sometimes people will add paint where it is missing,” says UAB art historian Katherine McIver, Ph.D. “That’s restoration.” In some museums, for example, gold leaf that is lost from Renaissance paintings is replaced with modern gold leaf.
But “the more modern concept is conservation—trying to preserve a work as it is without necessarily replacing any paint,” she says. The work done to Leonardo’s Last Supper in Milan and Michelangelo’s ceiling of the Sistine Chapel at the Vatican offer two examples. In both cases, watercolor was used to replace lost paint so that it would be clear to future historians which areas of the paintings were original and which were added. Conservation also helps protect art from a dangerous deep cleaning; McIver explains that restorers attempting to freshen paintings have sometimes rubbed away too much pigment or varnish. “Conservation is about keeping the art without trying to make it perfect,” she says.
When it comes to preservation, personal history is no less important than cultural history. But the methods of saving crucial health data are quite different—and changing rapidly. “Right now we’re in a hybrid print and electronic world,” says Joan Hicks, chief information officer for the UAB Health System, who oversees the collection and storage of patient data for the organization. “Previously we would print out everything and file it. Then we would preserve our clinical and administrative documentation with microfilm.” Now the Health System is transitioning to a new electronic medical records system, expanding the scope and detail of the gathered data. “When we began storing nursing documentation and physiological monitoring electronically, the volume of data increased significantly,” Hicks says. “We’re measuring everything in terabytes now.” (Ten terabytes would be sufficient to store the entire printed collection of the Library of Congress.)
Those terabytes are stored on computer servers, where they will reside for years to come, Hicks notes. “UAB made a decision many years to ago to exceed the retention time required by law,” which in Alabama is 10 years for adult patient records; for pediatric patients, records are kept until they are two years beyond the age of majority. “Academic organizations retain data longer from a research perspective,” she adds.
To protect the data for all those years, UAB outsources the storage function to electronic services off campus. When records are needed, an automated process prints and mails the relevant data. “The fewer hands that touch it and the less paper you produce, the more secure it is,” Hicks says. Patients also benefit from the approach, she adds. By giving referring physicians secure access to UAB’s electronic records system, patients “don’t have to depend on a fax or something like that. That could keep them from repeating a test.”
Hicks explains that data preservation is a constant and frequent topic of discussion in health care, driven by changes in federal law and the needs of patients, physicians, and researchers. And the questions evolve along with the technology to store data: “As we decommission storage systems, we have to ask ourselves what to do with the data. Do we keep it all or extract components of it? Do we move it to a network that is less costly and uses less energy?” Hicks says. “I’ve had two conversations about that today.”
Technology also is reshaping other realms of preservation. Levine, for instance, has embarked on a project to digitize the Visual Arts Gallery’s entire collection, which includes about 1,000 paintings, sculptures, ceramics, lithographs, photographs, and electronic works. “We’re capturing the highest-resolution image of every piece, as well as images of anything that can help us identify the work—a signature or anything on the reverse of the object,” he says. Though the project will take “forever” due to limited space and time, Levine hopes to build a comprehensive electronic database of art accessible by students, faculty, and staff.
How do you preserve your own archives—the family photos, finger paintings, and scrapbooks you want to keep forever? UAB archivist Tim Pennycuff offers a few pieces of advice:
1. Keep your items out of the attic, which is too hot and dry, and the basement, which is usually too wet and damp.
2. Don’t display framed art or photos in direct sunlight, which will cause fading over time.
3. Store items in folders, envelopes, boxes, and containers that have a little breathing room. Don’t put them in sealed plastic containers; paper products need some air.
Digital storage presents a dilemma, however. Unlike Leonardo’s 500-year-old drawings on paper, CDs or DVDs begin to degrade in as few as 20 years. And even if digital files remain intact beyond that time, the hardware and software to read them might be obsolete by then, says Pennycuff. Less than two decades ago, he recalls, the five-inch floppy disk was the standard storage device.
“Future historians will know more about the 20th century than this part of the 21st century because so much more was preserved before everything went digital,” says Pennycuff. And while the National Archives is developing new guidelines to help address these issues, “the generally accepted practice is to save things in a nonproprietary file format, which you don’t have to buy a particular type of software to use—and hopefully you’ll be able to access it later,” Pennycuff says.
Levine agrees that “there will never be a perfect way to preserve digital works.” But, he adds, “if we believe in the binary nature of digital media—that compiling something as ones and zeros is going to be the universal standard for digital information as far as we can see—then we can assume that capturing information in that way is going to have long-term viability.” For UAB’s art digitization project, Levine plans to house his files on a server and at least two backup hard drives. “I’m happy with whatever technology will allow us to access the work in the immediate future,” he says. “We invest so much time and effort into trying to keep things around, but entropy and the environment are against us. As long as we do the best we can now, we can’t worry about what will happen 300 years from now.”
New Life for Leonardo
Hundreds of years from now, modern artifacts may even be able to take advantage of technological upgrades. At the Birmingham Museum of Art, da Vinci himself received assistance from 21st-century wizardry. Thanks to an innovative computer program, visitors were able to page through a virtual copy of the Codex on the Flight of Birds, a famous notebook filled with Leonardo’s observations on bird flight and his ideas for a flying machine. (The actual book sat in a protective case nearby, opened to one set of pages.) The technology also translated the original text into English and animated three-dimensional models of Leonardo’s mechanical drawings.
That kind of digitization may not offer the best way to keep art or artifacts safe for all time, but McIver says it gives the Codex and other rare, historic pieces a new life by introducing them to modern eyes. “These works cannot be handled that much and are not kept on display,” she says. “The digital imagery helps preserve them by giving access to people who would never have a chance to see them.”