The X-Ray and the Eye

rothchild_topIn a corner of an industrial building just outside of New Haven, a woman points a gun at a treasured painting. The weapon is loaded, and she is ready to fire. She aims carefully, focuses, and pulls the trigger. But this gun shoots X-rays, not bullets.

As an X-ray strikes the canvas, it jumbles the electrons orbiting an atom of paint. The atom quickly reshuffles its particles in order to regain its former state of equilibrium. In doing so, the atom sends back another ray, which contains information about the painting. The gun swallows the ray and transmits the information to a laptop, which displays a graph cluttered with overlapping peaks of various heights. The woman shows me how the peaks correspond to elements: “Here, you see, this is copper, and here is lead. The lead is probably in a white pigment, called lead white.” No one, not even the painter himself, has ever known so much about this painting’s chemical composition.

The woman behind the gun is a chemist named Anikó Bezur. She is the director of scientific research at the Yale Center for Conservation and Preservation (CCAP), a multimillion-dollar facility built in 2012 to house and care for the University’s vast art collection. Yale owns more than 200,000 pieces of art, from pristine Roman busts of Julius Caesar to paintings by Monet and Van Gogh.

Bezur and her fellow conservators approach the works with extensive technological expertise. With the data obtained by scanners, lenses, lasers, and other instruments, the team generates scientific analyses that inform their approach to conservation. But despite the millions Yale has invested in the CCAP, the institution’s central philosophy—that scientific analysis should take the lead in informing conservation decisions—remains controversial, even among the curators at Yale.

The first time I meet Bezur, she is working on a painting stored outside the CCAP, in a building called the Library Shelving Facility (LSF). Located in Hamden, Connecticut, a ten-minute drive from campus, the windowless industrial building stores books, art, and other objects belonging to various Yale collections. Bezur greets me with a wide smile and shakes my hand. She leads me into a room filled with artwork placed on countertops and propped up on easels: the LSF’s conservation lab.

Bezur is there to examine the painting in the far corner of the studio, the one with the X-ray gun pointed at its surface. Called The Education of the Virgin, it depicts the Virgin Mary’s mother, St. Anne, teaching her how to read. The young Mary, draped in a dusky red robe, occupies the center of the scene, with her parents on either side.

For eighty years, the work was stored, unnoticed, in the basement of the Yale University Art Gallery. Without a signature or any other identifying features, it was one of many works of unknown origin. But in 2004, a junior curator named John Marciari unearthed it and showed it to his superiors. Convinced that the painting was the work of an identifiable artist, curators at the Gallery embarked on an international quest to authenticate it. Today, experts recognize the painting as a lost work by the Spanish master Diego Velázquez, one of the most important painters of the 17th century.

Held upright in the LSF by a large wooden clamp, The Education of the Virgin is severely damaged. Gashes mar its surface, a missing corner leaves an angel headless at the top of the painting, and abrasion has worn down much of the paint, disrupting the delicate brushstrokes that define Velázquez’s work.

Bezur is working on this painting alongside her colleague Carmen Albendea. Albendea worked on projects in Madrid, Los Angeles, Baltimore, and Cambridge, England, before coming to Yale in 2012 specifically to determine how best to treat the Velázquez in its cracked and injured state.

Her goal at the moment is to create a comprehensive picture of the chemicals that exist in the painting—the base coat, the paint, and the varnish—in order to treat the painting’s wounds.

But she also wants to study Velazquez’s painting process. To do this, she uses another tool, an X-ray radiography machine, to scan the canvas. This machine can reveal materials hidden beneath the top layer of paint to help the scientists understand the artist’s drafts and mistakes. A printout of that scan, around five feet tall and four feet wide, hangs on the wall. It looks like an X-ray you’d see in a doctor’s office: pearly white shadows outline Mary and St. Anne against a pitch-black background.

The printed scan reveals a small table in the left-hand corner of the painting. The table is laden with bulky objects, invisible in the real painting. The original sketch was painted over, and is now obscured by the resting arm of Mary’s father.

Armed with this kind of information, Albendea plans how best to repair the work. Some changes are scientific: She will choose a paint that can heal the cracks but is easily removable, in case a future conservator wishes to redo her work. Others are aesthetic: She will decide whether to repaint the angel’s missing head, or whether to leave it as a testament to the age of the painting. She will determine how best to replicate the delicacy of the brushstrokes that once covered the surface of the canvas. For now, Albendea is still gathering data to determine the next chapter in the painting’s story.

But some at Yale place less stock in science’s ability to aid conservators. Among them is the Chief Curator of the Yale University Art Gallery, Laurence Kanter, who also works as a professor of early Italian art in Yale’s History of Art department. When we meet, he wears a brown suit jacket and speaks in a low tone, barely audible over the bustle of the gallery, where he has worked since 2002. Kanter previously curated at the Metropolitan Museum of Art in New York City and the Museum of Fine Arts in Boston. He considers the data produced by scientific analysis to be decidedly secondary to the information that an expert eye can extract from a work of art.

“Science isn’t a way to prove anything,” Kanter says. “It’s just more evidence, more data. The proof is in the interpretation.”

Kanter strolls around the six galleries of early Italian art in the museum. He has played an important roll in acquiring the collection. We walk past ornate frames hung on walls of midnight blue. Mary, Jesus, and a collection of saints look back at us, their heads ringed by gold haloes.

Although the gold still shines, peeling wood on the frames and cracks in the paint reveal these works’ age: They were created by pre-Renaissance masters in the thirteenth and fourteenth centuries.

Over the past 700 years, many of these paintings have suffered significant wear. Exposure to harsh light has faded their colors; heat and moisture have warped the wood behind the paint; dust and dirt have settled in the cracks and yellowed the varnish that overlies the tempera. In some cases, the original works have been painted over by past conservators who thought they were improving or restoring the work.

Caretakers must carefully consider which cracks to fill with modern paint and how to repair large swatches of lost color. Kanter argues that a historian, not a piece of equipment, must answer these questions. He is well versed in the history of art conservation at Yale. Walking from painting to painting in the gallery, he recounts the conservation decisions that have determined the way the works look now.

“This is the problem,” he says. “Science and aesthetics are not compatible undertakings. They don’t need to be compatible. Nobody wants them to be compatible.”

To illustrate this point, he stops in front of a pair of portraits hanging side-by-side, one of St. Peter and the other of St. John the Baptist. A single artist of unknown identity painted this pair in Siena, Italy around the year 1320. The portraits are extremely similar: the saints look directly at the viewer, wearing slightly worried expressions.

Both saints sit on a backdrop of gold leaf. A thin circle—a halo—circumscribes their heads. Other patterns are impressed and inscribed between the halo and the head to alter the gold’s reflectivity. Just outside the halo is a concentric circle of triangular patterns composed of three small dots, punched into the gold to emphasize the contour of the halo.

Although the artist created the backgrounds of the paintings in the same way, they look noticeably different today. St. John’s portrait looks much like it did 700 years ago, with patterns of distinct circles ringing the halo. But St. Peter’s halo is instead surrounded by dull triangles, the three dots blurred together.

The difference was not an artist’s error, but a result of differing attitudes toward conservation.Yale conservators treated the painting of St. Peter, gouged with holes, in the sixties. They left the painting of St. John, with its pattern of delicate circles, untouched.

The modifications to the former painting reflect a certain trend in art conservation in the sixties. “There was a lengthy moment in [the art gallery’s] history,” Kanter says, “when the institution felt that all of its conservation practice should be guided by scientific inquiry, producing particularly horrifying results.”

In treating the painting of St. Peter, the 1960s conservator attempted to remove debris that had settled into each small hole punched in the pattern. Though he removed the dirt carefully, he also, inevitably, removed the tiny flakes of gold leaf that had kept the small holes separate and distinct.

“All he was interested in was the materials, not the impression,” Kanter says. “The dirt enhances the original effect; it doesn’t obscure it.”

The picture treated by conservators differs, too, in that its colors are stronger than those in the unaltered picture. St. Peter’s shirt is a bright cerulean blue; the book he holds is a strong scarlet. In contrast, St. John wears robes of faded brown. This difference, like that of the haloes, arose because conservators cleaned off St. Peter, rubbing off the yellowed varnish with chemical solvent, but left St. John alone.

“Is that more faithful to the original?” Kanter asks. “No. The only thing it’s faithful to is the original materials, not the original look or intention of the picture.”

Anikó Bezur and her team at the CCAP have a different definition of intention. Located in a former pharmaceutical building on Yale’s West Campus, the CCAP’s squat industrial façade cuts a rather figure, especially on a rainy afternoon. I arrive sopping wet in the lobby where Jens Stenger, a physicist who works at the CCAP, greets me and invites me to hang up my rain jacket on the hook next to his desk. We walk into the first lab of many, a spotless room glittering with dozens of new machines. Stenger pauses before each piece of equipment to explain its function. One machine reveals which molecules resonate at different frequencies, while another sorts molecules by their size, determining, in a few minutes, exactly which elements an oil painting contains.

Bezur joins us in a room housing an electron microscope, which is several feet tall and wide. We make small talk for a few moments before I ask her what she thinks about Kanter’s view of the relationship between science and conservation.

She bursts out: “You talked to Larry?” Then she laughs. I ask her what’s so funny. “I just think he has a…very different perspective,” she says diplomatically.

Bezur becomes more serious as she acknowledges the truth she sees in Kanter’s argument. She agrees that science has its limits. “There’s no scientific signature for Velázquez,” Bezur says. “It’s not like a unique DNA imprint, unless we were to find his hair and find a match; and short of that it’s very difficult to say that something was made by this person’s hand.”

Stenger too recognizes that there are certain areas of art study in which science is not at all useful. “If you’re really interested in all the stories and the history, you cannot uncover who Botticelli was friends with by looking under the microscope,” he says. “So there’s this huge area to which I think you can really securely say that science has very little or nothing to contribute.”

But Stenger and Bezur maintain that scientific analysis can and should be a large part of conservators’ decision making. Through analysis of pigments’ chemical structures, Stenger can determine how and from where an artist long ago acquired his materials, and how they were made. The chemical decomposition of a blue color tells him when the pigment was made, and a chemical analysis of the lacquer used in a varnish reveals the sap from which it was made.

Bezur does not devalue Kanter’s expertise. She maintains, however, that technological analysis of artwork is the truly objective measure upon which museum directors and others requiring artistic analysis should rely.

“For many, many centuries, people got along just fine without the scientists,” she says. She pauses, then continues sarcastically: “And I love going into storerooms and finding the half a million dollar mistake that was just based on a good eye and plenty of experience.” She laughs. “That’s all I have to say.”

Kanter and other conservators who rely on their own eyes for interpretation are not exactly Luddites. “An artist like Velázquez is more complicated than any other artist,” Kanter concedes, “because his painting technique was so subtle and so complex that the more you can learn about it—including its elemental component materials—the better prepared you are to know how to overcome issues.”

The knowledge gained from Albendea’s radiography scan of The Education of the Virgin can deepen art historians’ understanding of Velázquez’s painting process. The information is undoubtedly useful for certain kinds of research and analysis. But Kanter insists that this data remain secondary to expert opinion when it comes to restoration, because technology creates credulity: “People are willing to believe whatever an instrument with a needle on it will tell them, thinking that that is the answer, a Geiger counter.” He maintains that care must be taken to use scientific analysis only as supporting evidence, and never as a definitive answer.

But the curator and the chemist often have a common goal: preservation. The master artists of the past conveyed their visions using fragile materials, and we’re left to deal with the decay. Bezur and Kanter are shuffling through the debris using different techniques, and each is wary of the jurisdiction of the other. Both are trying to speak up for artists long gone. If only the artists could speak for themselves.