Under the paints and pigments, the science behind art restoration

    Detail from Pietro da Cortona's 17th century painting

    Detail from Pietro da Cortona's 17th century painting "The Triumph of David" at Villanova University (Lindsay Lazarski/WHYY)

    How does science play a role in restoring an elaborate 17th Century painting? 

    To restore a painting, it takes a village, a team of art historians, conservation experts and cultural sleuths. Right now a 17th century painting, long abandoned at a dusty Villanova University library, is being brought back to its past glory.

    For almost 60 years, the Faley Library at Villanova University held a hidden treasure in plain view — an enormous painting hanging high on the wall. But it was so dark and deteriorated that few noticed it. That all changed when a group of Villanova scientists and art historians decided to do something about it.

    Separated from the rest of the library by a 10-foot-high chain-link fence with pad-locked doors, is the restoration site of the 17th century canvas. The painting, “Triumph of David” by Pietro da Cortona, was donated to the university in 1950. 

    Going beneath the surface

    The first step in approaching the painting was to bring a team from the prestigious University of Delaware Art Conservation Department to take a look at it. Lead conservator Kristin deGhetaldi remembers that, when she first saw the canvas, it was so damaged she wasn’t so sure about the condition.

    So she climbed a scaffold, took a closer look, and took some miniscule samples and handed them over to Dr. Anthony Lagalante, science and chemistry professor at Villanova and the principal scientist in the restoration project.

    He applied advanced analytical techniques to study and identify individual pigment particles. So, Lagalante says, “if Kristin wanted to know exactly what this blue is, we were able to establish how the artist worked, and dug through layers of paints and pigments, about 15 in this case, and figured out what was behind the surface of what we see to the naked eye, to establish the combined reflection and absorption of light.”

    The tests revealed the chemical composition of the paint, an important factor in deciding what cleaning solvents to use. Importantly they also revealed that, under the varnishes and repainting of overeager, amateur restorers lay a true treasure.

    “Lo and behold,” says deGhetaldi, “there were these brilliant, beautiful colors underneath,” sparking the idea of conserving the painting.  

    Faced with this rare opportunity to have total access to an old canvas of this importance, chemistry professor Lagalante decided to use the painting as a living lab, a hands-on classroom, so to speak, to explore the many intersections of art, science and new technology.

    Early radiology and spectography was pretty primitive, says Lagalante, but now they’re able to use advanced military techniques and technologies on paintings. It allows the team to look inside the painting in a non-destructive way and to find how Pietro da Cortona and his apprentices worked in his workshop near Rome.

    He was a sought-after painter who worked on huge canvases and frescoes commissioned by wealthy families and the Catholic Church. Da Cortona’s “Triumph of David,” painted around 1620, depicts a joyful Biblical scene of the shepherd David delivering the head of Goliath to King Saul.

    The parade has almost a cinematic quality. Villanova art historian Timothy McCall, who is part of the restoration team says, “You get the sense of dynamism and movement. You can almost hear this painting.”

    From Rome to Villanova

    So how did this Baroque canvas end up in a Villanova University library? The story reads like a novel; there’s love, death, greed, and the ravages of World War II.

    It starts in the late 1920s when Alabama-born heiress Jenny Berry married a young Italian prince she met in Washington, D.C., diplomatic circles.

    Berry, now Princess Eugenia Ruspoli, says McCall, “was about 40 years old. He was in his early 20s, had a name but not a lot of money. With her money they bought a castle where this painting had been.”

    Then the castle was bombarded during the Second World War’s Battle of Rome in 1944. 

    “U.S. troops were involved in the battle of Rome at Castle Nemi,” adds Anthony Lagalante. “It’s assumed that some of the damage to this painting was done during World War II, but we have no way of knowing.”

    No one knows for sure how the artwork made it out of the castle and ended up in the United States, but what’s documented is that the princess met Villanova University’s Father Faley as he was raising funds for a new library and persuaded her it would be a good place for Pietro da Cortona’s “Triumph of David.”

    An open forum

    The entire restoration process will take approximately two years and, by now, almost half of the bottom part of the big canvas has been cleaned. The work is painstakingly slow, as scientists analyze each segment and seek the best techniques to unlock the secrets the canvas holds.

    To do that, science professor Lagalante is also applying a technique called molecular imaging, which he says is a method of deeper analysis based not on the color or the absorption of light, but on how much a molecule weighs. 

    Since it’s a university library and not a museum, students and the public can watch, get near or behind the canvas and talk to the conservators. There’s not a lot of action, but there is excitement in the air, especially when a new detail, like a face, emerges — or when a bunch of unattached feet suddenly appear.

    There’s a reason and a name for that surprise, says Kristin deGhetaldi. “We begin to see things that the artist never truly intended us to see. They wanted to cover up this area here, because they decided to change it. When we first started, we saw evidence of eight different feet in this group down here, it’s called ‘pentimenti.’ When you have a painting of this size with multiple hands at work, there are going to be a lot of changes, and this is something that is commonly associated with his large painting. We know this for a fact.”

    The team knows it can never bring da Cortona’s “Triumph of David” completely back to its original glory, confesses deGhetaldi. Still, this collaborative effort will leave behind an enormous sense of achievement and new scientific knowledge in the art of restoration.

    For details on the restoration process and scientific research, visit the project’s website

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