He did, and voilà! He had his proof. With time and media attention, some Turner scholars were persuaded that Biro was onto something. In 1995, Landscape with a Rainbow was attributed to Turner—the first painting to be authenticated based on fingerprint evidence—and it was sold at the Philips Auction House in London for more than $150,000. (It would have sold for more had it not been in poor condition.) For Biro it was a case of determining the painting’s “forensic provenance.”
Thus began a passion and a career. For twenty years, Biro applied the forensic methods used to solve crimes to the mysteries of art attribution. As part of his database, he conducted an ongoing study of the works of Turner in the Turner Bequest at the Tate Britain gallery, comprising some thirty thousand pages of notes, sketches, and watercolors. He discovered about a thousand fingerprints and hoped to eventually compile up to three thousand. He liked to quip, “The issue is not who committed the crime but who committed the painting or drawing.”
What excited Biro most about the science was the way it opened up new possibilities in art authentication. Traditionally, art had been authenticated by the inexact methods of provenance and connoisseurship. Provenance was the art’s historical paper trail, which was often sketchy, especially for very old pieces. One hoped for provenance but expected disappointment. Connoisseurship relied on the expert’s eye: the ability to compare one work with another and judge whether it was drawn by the same hand. Connoisseurship was by nature subjective. Biro believed that with fingerprint evidence, a work of art could literally be traced back to the artist’s hand, and in that respect it could fill in the blanks from history or knowledge.
Biro never tired of talking about the marvelous science of fingerprints. He found that in the early twentieth century, mathematical analyses predicted the possible existence of sixty-four billion fingerprint patterns, considerably more than the present human population of the planet. Every fingerprint was an original; however, the individuality of a fingerprint was not determined by its general shape or pattern but by the configuration of its ridge characteristics: the combination of a number of characteristics in a given finger impression that are specific to a particular print.
There are three basic types of fingerprints: latent fingerprints, stamped impressions, and plastic impressions. A finger may leave a latent print due to the presence of fatty substances produced by the sebaceous glands in the skin. This is the kind of print found on objects such as drinking glasses and windowpanes. It is called latent (invisible) because it requires development with black powder or iodine fuming to make it visible. A latent print cannot survive for long.
A stamped impression is a mark left with whatever material contamination was present on the finger (such as ink or paint). The longevity of the fingerprint is contingent on the longevity of the substance deposited. If that substance were oil paint, the print might, if conditions permit, be preserved indefinitely.
A plastic impression is left when the finger was impressed into soft material, such as partly dried paint, putty, wax, or a similarly pliable substance; in other words, it can be seen in relief. The longevity of the impression again depends entirely on the substance, combined with other environmental factors. Under the right conditions, however, oil paint can preserve a plastic impression indefinitely.
Biro was quick to explain that contrary to popular belief, fingerprint analysis is not an exact science. The final verdict relies on an analysis of points of similarity in the prints, generally ranging from seven to twelve. Identifying fingerprints on works of art is even more delicate and difficult than for crime cases. For one thing, crime labs use methods such as staining and dusting that potentially destroy the object, whereas the art examiner must guard against any destruction and normally relies on images rather than the original. In addition, the art investigator does not look for latent prints—the kind left on a glass or other surface—because they break down quickly and would not be there to find.
Biro was focused on prints that were clearly left by the artist during the creation of the work. “Such evidence,” he said, “has temporal ramifications, the print having been sealed in time, creating a veritable time capsule from when the picture was executed.”2 However, he acknowledged that an old painting always suffers from wear and tear, the effects of chemical and physical pollutants, and the rigors of cleaning and restoration. In these cases fingerprints could suffer as well.
The multispectral camera opened up possibilities that didn’t exist before of enhancing barely visible prints to the point where comparisons could be made. He observed that the new technology “enables the isolated amplification of the fingerprint information against its background, eliminating other interference such as ‘noise’ created by the imaging device.”3
Biro was confident that an investigation of fingerprints in the work of great artists was a valid occupation. “Artists have used their bare hands in the creative process—employing their fingers to evoke a variety of effects—ever since prehistory,” he noted. “The potential for fingerprints to be left on the surface of their work, either by accident or by design, is thus hardly negligible. In the Renaissance, for instance, both Raphael and Leonardo relied on their fingertips to stamp fine ridges onto their paintings and create delicate and subtle evocations of shading unattainable with the brush.”
Of course, as in any forensic investigation, the primary question in identifying fingerprints is whom did they belong to. The artist? Assistants? A restorer? This is where the database came in handy. Biro had been able to authenticate Turner’s prints by comparison with others. Might the same be done with a potential Leonardo?
By the time we decided to send the digital file to Biro for his review, he was already quite well known because of his involvement with the authentication of an alleged Jackson Pollock painting.
The story of the Pollock painting epitomizes a popular fantasy about great art: that it is hiding in plain sight in the attics, flea markets, and yard sales of the world. The story of this painting, which was memorialized in a 2006 documentary, Who the #$&% Is Jackson Pollock?, directed by Harry Moses, fits into that mode. It was also the subject of a 60 Minutes report on May 6, 2007, titled, “The Thrift Shop Jackson Pollock Masterpiece.”
Teri Horton was a seventy-three-year-old retired long-haul truck driver from California who came upon a wildly colorful painting in a thrift shop. She bought it for $5, thinking it would be perfect to cheer up a friend who was down in the dumps. She had no inkling that it might be a valuable piece of art. In any case, the 48-by-65-inch painting was too big to fit through the doorway of her friend’s trailer, so Horton decided to sell it at a yard sale. There it was noticed by a local art teacher who declared he thought it might be a Pollock, causing Horton to say, famously, “Who the f— is Jackson Pollock?”
In the film, Moses said, “I think that the evidence threatens scholarly expertise. Connoisseurship no longer plays a dominant role in authenticating works of art. The art world thinks it can dismiss Teri because she’s a truck driver. My movie is a story about class in America.”
It’s a fascinating aside—a controversy that pitted an ordinary woman against the snobbiest of the snobs of the art world. If anyone characterized the unappealing elitism of the art community, it was Thomas Hoving, the former director of the Metropolitan Museum of Art. Asked to review the painting, he sniffed at it dismissively and declared, “This painting has no artistic soul.” (I had my share of disputes with Hoving. Before he died, he saw a photograph of La Bella Principessa and declared it “too sweet” to be a Leonardo, explaining that Leonardo’s pictures were “tough as nails.” I couldn’t begin to fathom what he was talking about.)
Teri Horton clearly enjoyed the spotlight and especially her status as an outlier in the snooty art world. Interviewed by CNN journalist Anderson Cooper on July 16, 2003, she said, “There is no way anybody can get up and look at that painting, or any Pollock for that matter, and be able, by visual examination and wait[ing] for this mystical
feeling that they get that comes over them, to decide whether it is or whether it is not authentic.” She added snidely, “They call it connoisseurship”—stretching it out as if it were a dirty word. Asked by Cooper what she would call it, she laughingly replied, “Bulls—.”
In the midst of the efforts to authenticate the Pollock painting, Biro was hired. After finding a partial fingerprint on the back of the canvas, he set out to look for a fingerprint impression of Pollock’s to which he could compare it. Pollock had never served in the military or been arrested, so his fingerprints were not on file. Biro visited Pollock’s studio in East Hampton, New York, where he found a fingerprint on a blue paint can used by Pollock. He concluded that the two fingerprints were a match.
Biro checked his work with André Turcotte, a retired Canadian police sergeant who ran the Quebec Police fingerprint lab for more than a decade. Turcotte agreed that the prints matched. But the International Foundation for Art Research, a nonprofit organization that is the primary authenticator of Pollock’s works, balked, saying that Biro’s method was not yet universally accepted.
Complicating the question was the complete absence of any known fingerprints by Pollock. There was no possibility of making a real comparison. Biro’s only option was to build a case through a preponderance of evidence. He could only make cross-comparisons. Nonetheless, he believed he had one important factor in his favor: fingerprinting had been around for more than a century as a true science. There were no gray areas. There was no room for error or review. Done properly, fingerprint analysis shows a match or does not show a match. Nevertheless, the Pollock attribution remains in limbo.
After his experience with the Horton “Pollock,” Biro threw himself into the work with more fervor than ever. He cofounded a company dedicated to the use of scientific methods to help the art community wrestle with these tricky and often controversial issues. He set up laboratories in London and Montreal. His dream was to be at the forefront of an entirely new field: utilizing DNA as evidence in artwork. The old way and the new way were perhaps on a collision course. But it was exciting to watch.
In his workshop, Biro studied Pascal’s digital work on La Bella Principessa with great care. Lumiere Technology’s multispectral images revealed two specific impressions on the drawing. One was a stamped impression in ink of a finger near the upper left edge of the vellum. The other print was a plastic impression in the subject’s neck, which appeared to be from the outer edge of the artist’s hand.
There was plenty of evidence to support Leonardo’s use of fingers and hands to blend in shade. As Martin noted, during the period in question, “Leonardo was pushing his chalk techniques in a painterly direction . . . confirmed by the handprint visible in the Lady’s neck, assuming that it is deliberate and not accidental. His paintings before 1500 show extensive use of the fingers or hand to blend the modeling, particularly in the flesh tones. It generally looks as if the soft, fleshy area of the right edge of his right hand was used for this purpose, while he applied the media with his left hand. While he was not unique in exploiting his fingers and hands in paint or priming layers, he did use the technique in a typically widespread and varied manner. It is likely that more handprints were visible in the flesh of La Bella before the restoration(s).”4
Biro also examined a number of images from Lumiere Technology’s database, including the Mona Lisa and Lady with an Ermine. He found that all of the works contained both fingerprints and palm prints that could be used for comparison.
What, specifically, was he looking for? For two fingerprints to be considered a match, they must be compared in accordance with basic principles, such as being reproduced to the same scale and presented in the same orientation. If these conditions exist, one of three levels of correspondence is possible.
Level one involves a comparable flow of ridges, showing a similar pattern of loop, arch, whorl, and delta (which are the identifying fingerprint marks). Level-one comparison narrows the field of contributors while not being entirely conclusive. For example, twins often have very closely matching prints, and a finer level of detail is needed to see the difference.
Level two involves more detailed characteristic ridge patterns and deviations. If two prints correspond in level-one detail, then the examiner proceeds to look for level-two detail, involving the bifurcations, crossovers, ridge endings, and so forth. “Characteristic” patterns are essentially deviations in a ridge’s path. When a ridge’s path divides into two branches, it is called a bifurcation. When two bifurcations appear on the skin overlaying each other, they are called a trifurcation. If these are found in the comparisons in the same basic position, it’s a match.
Level three involves the minutest aspect of ridge impressions, such as the outline of the ridges and the placement of sweat pores.
The number of corresponding features necessary for a match is not uniform from country to country and is generally left to the examiner’s discretion and expertise.
For Biro, the work that was the most fruitful was Leonardo’s unfinished St. Jerome in the Wilderness at the Vatican, which contained more than two dozen fingertip impressions left in the wet pigment, clearly used to shape the underpainting for the background of sky, water, and rocks. St. Jerome in the Wilderness was significant because it was painted early in Leonardo’s career, before he had apprentices. There was no doubt that he was the only artist to touch the painting at that time.
The digital enlargement of La Bella Principessa helped Biro to recover ridge-path detail at a resolution approaching what was necessary for fingerprint examination. It revealed a number of recognizable characteristics that could be compared with those of a digitally enhanced fingerprint on St. Jerome in the Wilderness. Biro singled out eight characteristics discernible on both prints. He concluded that the correspondence between the fingerprints on Leonardo’s St. Jerome in the Wilderness and La Bella Principessa provided a highly valuable piece of evidence. Although it might not be sufficient to establish innocence or culpability in a legal case, the coincidence of the eight marked characteristics was strongly supportive of Leonardo’s authorship of La Bella Principessa.
To further strengthen his findings, Biro gained access to a high-quality photograph of an X-ray of Leonardo’s Ginevra de’ Benci, which was on display at the Washington, D.C., National Gallery of Art. He discovered a fingerprint that was similar to the others.
Biro found the examination of Leonardo’s fingerprints thrilling, because their presence revealed so much about the genius of the artist. Leonardo used his fingers and palms as extensions of the brushes—he got literally down into the painting, working it over as if he were sculpting. Leonardo’s brilliant and effective use of the ridges on his fingers and hands clearly contributed to the subtle and sublime effects he created here and in so many of his works. It revealed the imaginative and ever exploring creative mind for which he is so revered.
Martin believed that the fingerprints, though not conclusive on their own, added an important piece to the puzzle. He wrote to me, “This is yet one more component in what is as consistent a body of evidence as I have ever seen. I will be happy to emphasize that we have something as close to an open and shut case as is ever likely with an attribution of a previously unknown work to a major master. As you know, I was hugely skeptical at first, as one needs to be in the Leonardo jungle, but now I do not have the slightest flicker of doubt that we are dealing with a work of great beauty and originality that contributes something special to Leonardo’s oeuvre. It deserves to be in the public domain.”
The jury is still out on the fingerprint evidence as full proof of a Leonardo attribution. Jean Penicaut is in the process of attempting to obtain permission from Vatican authorities to digitize Leonardo’s St. Jerome in order to properly compare the fingerprints. This is a scientific study in progress, quite promising, but ongoing nevertheless. Even so, when I read Biro’s report, I saw one more piece of a complex puzzle leading to Leonardo.
It was time, at last, to
introduce the world to Leonardo’s beautiful princess—once lost but now most assuredly found. Little did I know the upheaval that awaited me.
10
The World Reacts
The greatest deception men suffer is from their own opinions.
—Leonardo da Vinci
Katsushika Hokusai, one of the world’s great artists, who lived between 1760 and 1849, famously exclaimed on his deathbed at eighty-nine years of age, “If only heaven will grant me a few more years, I will become a real painter.”1 To that I can say without false modesty that if heaven grants me a few more years, I might just understand a little about art. Certainly, the moment the news of La Bella Principessa hit the world, I began my education anew.
It’s not as though there had been complete silence about the project. In the summer of 2008, while Biro was still making his fingerprint study, details of Lumiere’s findings began to leak out to the press. Pascal was openly saying he believed the work was by Leonardo, and the buzz began.
The press was interested in tracking down the dealer who had bought the portrait at the Christie’s auction in 1998. In the beginning, it wasn’t publicly known, and that was mostly my doing. I had decided to be a gentleman and withhold Kate Ganz’s name. It was a small deception, made to save Kate the embarrassment. I didn’t want to cause her problems by highlighting how she’d kept Leonardo in a drawer for nine years. I thought my motivations were quite honorable. But Kate didn’t see it that way.
When the first media coverage appeared about the portrait, Kate herself contacted the New York Times and said straight out—and somewhat indignantly—that she was the previous owner.2 She was clearly incensed by the suggestion that she’d missed a Leonardo, and she wanted to defend herself. However, I found her explanation somewhat disingenuous. She told the Times that she had considered a Leonardo attribution when she bought the work but had rejected it after consulting a number of art historians and a conservator at a major American museum.
Leonardo's Lost Princess: One Man's Quest to Authenticate an Unknown Portrait by Leonardo Da Vinci Page 11