The Triumph of David was a mess.
Old, original paint on the 17th-century canvas was faded and flaking in many spots. Newer paint from several inexpert restoration attempts had become discolored.
Standing before the massive painting at Villanova University, art conservator Kristin deGhetaldi could tell all this with her experienced eye. But in order to bring the painting back to life, how could she tell where the old paint ended and the new paint began?
The answer: a mix of art and science.
The 12-by-19-foot painting, thought to be the work of Italian artist Pietro da Cortona or one of his close associates, is in the midst of a two-year, $100,000 conservation effort.
Researchers have used an array of advanced scanning techniques to determine the chemical composition of various layers of pigment to help deGhetaldi and her team decide which layers to remove and which to stabilize or leave alone.
In September, university officials brought in technicians to X-ray the painting and were surprised to find a mystery figure hidden beneath the surface.
It all began in 2006 with chemistry professor Anthony Lagalante, who teaches a science course for non-majors on the chemistry of painting. He was looking for artwork on campus that his students could see in person.
The Rev. Richard Cannuli, curator of the school collection, told him about the painting attributed to Cortona - an architect and artist probably best known for his ceiling fresco in the Barberini Palace in Rome.
Largely forgotten by the outside world and in grave disrepair, the school's purported Cortona hung in an old wing of Villanova's Falvey Memorial Library that was used to store boxes of microfiche.
Lagalante, himself an avid painter, was stunned.
"You look up on the wall, and there's this giant painting that is clearly suffering," he said. "How did this painting come here? Why is this here in this media room?"
He learned it had been given to the university in 1950 by Eugenia Ruspoli, the American-born wife of an Italian nobleman. Other faculty members, including art historian Tim McCall, agreed with him that the biblical scene, which depicts David's triumph after slaying Goliath, was worth saving. Experts from the Philadelphia Museum of Art also were consulted.
The university eventually hired deGhetaldi, an independent conservator who also is a Ph.D. candidate in preservation studies at the University of Delaware. She and a team of interns got started in fall 2013.
The work has involved a heavy dose of science, with assistance from Lagalante and others in the university chemistry department. Team members used a handheld device that measures how different regions fluoresced in response to X-rays - a technique that gives a snapshot of the elements in the paint.
Among other findings, the device indicated the presence of a zinc-based varnish, a kind not used in the 17th century. It was clearly applied in a restoration attempt, so deGhetaldi and her crew had to take it off, with the judicious use of solvents, in order to work on the original surface beneath.
The device also revealed chromium and barium in the yellow shirt of a soldier at the left of the painting. Those two elements were not used to make paint until the 1800s. They were clearly applied during an imperfect attempt at restoration and had to be removed.
But X-ray fluorescence gives only an overall reading; it does not indicate which layers of the paint contain the elements in question.
So in some cases, the conservation team removed tiny flecks of paint from areas that already were flaking. These were studied with a scanning electron microscope - which can magnify its target many thousands of times - and special software that revealed the elemental composition of each layer.
Guided by these findings, deGhetaldi and her team have removed about 90 percent of the unoriginal varnish and discolored, unstable paint from restoration attempts - as much as they could without harming the original layers beneath.
They now are using modern conservation paints to fill in damaged areas and match the artwork's surrounding original hues. These special resin-based paints are stable yet easily removable, if better techniques emerge in the future.
In September, with money from the Samuel H. Kress Foundation, the university hired a team from General Electric to take X-rays of the vast canvas.
Among other surprises, the X-ray films showed that beneath a soldier's shield was the hidden image of a man holding a fasces - a bundle of wooden rods with an ax blade that was a symbol of power in ancient Rome.
The paint used in the shield appears to be from the 17th century, so as near as the team can tell, the man was covered up soon after the painting was completed.
"Clearly, they decided they had to get rid of this figure," said McCall, the art historian.
But why? Did the artist change his mind about the composition? Did a wealthy patron want the figure blacked out?
That and other mysteries remain, such as who painted the wall-size canvas, when, and for whom. McCall, Lagalante, and deGhetaldi will go to Rome in March to meet with experts who may be able to help.
But in the meantime, the conservation effort has already sent a jolt through the world of those who study 17th-century Italian art.
David Stone, a University of Delaware art historian who has visited the project several times, said the progress so far was exciting. A specialist in the Italian painter Caravaggio, he also is well acquainted with the work of Cortona.
But not this one.
"I had never heard of it," Stone said, "because if I had, I would have been there the next day."