The Enduring Challenges of Authenticating Art

The Enduring Challenges of Authenticating Art
Fourier Transform Infrared microscopy at work, one of the tools used by authenticators in today's art world. Courtesy Flickr Commons.
Leading lights  -   Experts

When the Allentown Art Museum sent their oil-on-oak painting Portrait of a Young Woman to specialists at New York University to be cleaned, they expected to get it back without the layers of overpainting and thick varnish which had obscured the portrait’s delicate brushwork. Since they weren’t immediately looking for any proof of authentication, they didn’t expect to get it back with Rembrandt’s name attached to it.

The painting had long been attributed to the great Dutch painter’s studio, but closer investigation by both NYU conservators and outside experts—who used everything from electron microscopy to X-rays to comb over the artwork’s every detail—confirmed that it was in fact painted by Rembrandt himself. The newly rebranded painting is sure to garner significant interest when Allentown puts it on public display starting June 7th—and, if the museum were ever inclined to part with their masterpiece, could pick up millions for it.

Before and after restoration of the Allentown Rembrandt.


How exactly do art experts determine that a painting is genuine? What small strokes of the brush or flecks of paint offer clues that a painting is the work of a great artist, rather than a forgery or a later copy?

The other da Vinci

When an expert’s assertion that a painting is genuine can mean the difference between a cheap copy and a priceless masterwork, tensions understandably run high. One of the earliest examples of an authentication drama playing itself out in the public eye led to “the most sensational art trial of the 20th century”. Unsurprisingly, the electrifying dispute centred around one of the world’s most beloved artists: Leonardo da Vinci.

“La Belle Ferronnière”, a painting once attributed to da Vinci, which was gifted to Harry Hahn and his wife, Andrée Lardou. Courtesy Wikimedia Commons.

In 1919, a newlywed couple—American car salesman Harry Hahn and his French wife Andrée Lardoux, whom he met while serving in the First World War—was gifted a painting. The painting, La Belle Ferronnière, was at the time, thought to be by da Vinci. Given that da Vinci only has a handful of paintings universally accepted to be his, the painting was surely an exciting gift and a very valuable one at that. What’s more, at the time Harry and Andrée Hahn received the sumptuous wedding present, the Renaissance master was particularly in vogue. Just eight years before, the Mona Lisa had shot to stardom after three Italians stole it and spirited it out of the city. Before its theft, the lady with the enigmatic smile had been largely unknown outside circles of art experts—but after the daring heist, queues of people formed to look at the empty space where the da Vinci had been.

The Hahns, then, were understandably excited to receive what they thought was the original da Vinci painting La Belle Ferronnière—the version hanging in the Louvre, they posited, was a copy, switched out some time in the 1800s. The couple tried to sell the artwork to the Kansas City Art Institute for around $250,000 – for reference, that would be around $3.2 million today.

Duveen’s wrench in the works

The prospective sale, however, as the beginning of the end of the Hahns’ da Vinci dreams. A local reporter caught news of the sale and reached out to Joseph Duveen, an art dealer and collector who, at the time, was essentially the authoritative figure on works by Old Masters and “America’s First Mega-Dealer.” Duveen was quite a character. Suave and flamboyant, he had built a lucrative business centered around his observation that “Europe has a great deal of art, and America has a great deal of money”. Duveen served not only as a purveyor of fine art, but as an intimate advisor, recommending which paintings were tasteful and valuable, to the biggest railroad magnates and financiers of the day.

Joseph Duveen in the 1920s, around the time when he questioned the authenticity of “La Belle Ferronnière.” Courtesy Wikimedia Commons.

Duveen—despite never having looked at the Hahns’ painting himself or even a photograph of it—did not hesitate to weigh in with his opinion on its provenance. This wasn’t out of character for Duveen—the suave dealer was a master of stirring up controversies which got his name splashed across the front pages and drew attention to his art business.

In order to gain wealthy financier Henry Clay Frick as a client, for example, Joseph Duveen insisted that one of his rivals, London dealer Edgar Gorer, had sold Frick some fake Chinese porcelain. The allegations devastated Gorer’s reputation and saw Duveen sued for $575,000 in damages—in a surreal twist of fate, the same day that news of the lawsuit made the front page of the New York Times, Gorer died aboard the Lusitania when it was struck by a German U-Boat—but kicked off the partnership between he and Frick that culminated in the masterful Frick Collection museum in Manhattan. Duveen undeniably sought to stir up further press-generating controversy when he confidently proclaimed that the Hahns’ Belle Ferronnière was undeniably not by da Vinci.

The painting’s owners, unsurprisingly, didn’t appreciate Duveen’s interference, and proceeded to sue Duveen for $500,000 for slander of title. The suit dragged on for years and the trial, packed to the rafters, went on for a month. The tremendous challenges involved in decisively attempting an artwork’s attribution were on full display during the trial. The judge referred to a previous case to underline the subjective nature of art attribution—“there being no way of tracing the picture itself, it could only be a matter of opinion whether the picture in question was the work of the artist whose name it bore, or not”. Duveen assembled a squad of some of the art world’s greatest experts—including art historian Bernard Berenson and Sir Charles Holmes, then the director of the National Gallery in London, to intervene on his behalf. The Hahns’ lawyer tried to enter what he called “fingerprint testimony” into the mix—“it was da Vinci’s habit to soften the wet paint with his finger (sic) tips, and such digital prints remain clearly defined on La Belle Ferronière”, he argued. In the end, the trial ended in a hung jury and Duveen settled out of court and paid the couple $60,000.

A hundred years later, the authenticity of the painting is still uncertain, though the general expert consensus is that Duveen was right in rejecting the possibility that it was a genuine da Vinci out of hand. The painting is still highly prized, however, it soared past Sotheby’s own expectations to sell for $1.5 million in 2010, credited to a follower of da Vinci. What’s more, we are no closer to having a definitive answer on how to authenticate a work of art than in 1919.

Hurdles for authentication

Authentication seems like it should be fairly straight forward, and in some cases, it is. When an artist is still alive, for instance, it can be easy to determine works that they created. But when you’re dealing with an artist who has been dead for centuries, as in the case of the da Vinci, things can become quite grey.

Traditionally, deciding what pieces were and were not an original work by an artist was a job left up to an authenticator or an authenticating body. Although an authenticator is crucial to the process today, there are now more tools available to separate the wheat from the chaffs or the real from the fake. There are also a lot of hurdles, much like there was for Duveen, when you’re in the field of authentication.

Being an authenticator means being a connoisseur of art. Most authenticators have studied an artist, or an era of art, closely. In many cases, they’ve taught on the subject, written scholarly works, examined dozens if not hundreds of works by an artist, and formed exhibitions around the artist they work with. “The most important tools and resources are actually my own knowledge of the work itself and the contacts I’ve cultivated during the forty years I’ve spent in the art world,” said Richard Polsky Art Authentication, who specialize in works by Warhol, Basquiat, Haring, Pollock, and Lichtenstein, in an email to Art Critique. An authenticator develops what Michael Daley, director of ArtWatch UK, an art conservation group, described as “forensic looking.” Modern authenticators rarely decide on an artwork’s validity without looking at it in person– mistake number one for Duveen, perhaps? – and they do everything from examine the surface of the work for cracks, known as craquelure, to listen to the work’s surface with a stethoscope. They also make use of the expertise of fellow authenticators when examining works. “Think of it this way,” continued Polsky, “To be able to successfully authenticate a work of art, you have to balance supreme confidence in your judgement, coupled with enough humility to realize that you can never assume anything.”

Traditionally, the authenticator’s word has been worth its weight in gold. An “okay” from the Andy Warhol Foundation 20 years ago could make your silkscreen print worth thousands, if not millions. In addition to individual authenticators, estates of artists who had passed away, including those by Warhol, Basquiat, and Pollock, set up authenticating bodies to somewhat regulate the market and validity of the artist’s work in their death.

The role of an authenticator has become even more important as art world spending has soared. In the last three decades, the price tags on paintings and the amount people are willing to pay at the auction block have ballooned. For reference, in the mid 1980s, Andrea Mantegna’s Adoration of the Magi was the most expensive artwork to have sold when it was purchased for $10.4 million. With so much money at stake, fakes and forgeries became more prevalent—not to mention the fact that a seal of approval confirming that a work was by a particular artist meant more money could be made.

As the prices paid for art at auction and in private sales have soared, the authenticator’s job has become even trickier. Photo: George Torode / English PEN

What makes an authenticator throw in the towel?

One might expect that the art world’s growing prices would drive up the number of authenticators in the world. On the contrary, today, the number of authenticators is dwindling. There’s one major reason for this: when hopeful collectors discover that the Monet they thought they owned is actually a clever forgery, their disappointment and frustration can be acute—so acute that they have frequently lashed out against authenticators who didn’t tell them what they wanted to hear. To quote Polsky, “the stakes have become much higher. Blue-chip works of art have become so valuable, that you have to minimize your risk when you buy or sell one.”

Lawsuits against the authenticator who dashed their hopes are common—while in some extreme cases, this retaliation has reached the level of death threats. As a result, authenticators and authenticating bodies have been scared away from putting their opinion out there, even if it means letting more fakes into the market. To make matters worse, art schools are focusing less on analyzing artworks and more on the philosophical and social implications of art, meaning that less people are graduating with established skills needed to become an authenticator. This creates a worrisome cycle in which the market becomes less regulated, calling for more authentication, yet few are actually willing or able to authenticate the works.

Speaking of regulation, the art market is actually the third most unregulated market today, falling in line behind the markets for drugs and sex work. Thomas Hoving, who was the director of the Metropolitan Museum in New York until 1977, has seen and handled tens of thousands of objects in his life. Throughout his career, he’s seen artworks that were deliberate forgeries, misattributed, and works that were poorly restored, leading him to “believe that there are as many bogus works as genuine ones.”

On the flip side of the authenticator’s argument for stepping away from stating their opinion on a works is that of the owner. In the past, owners of art who put forth works to be authenticated only to have them denied as originals have felt that the authenticating body was more interested in keeping an artist’s market tight. Thus, restricting the number of artworks in an artist’s oeuvre in order to drive up prices to the authenticator’s benefit.

Portrait owned by Joe Simon-Whelan, which was rejected twice by the Andy Warhol Foundation and now bares two infamous “denied” stamps on its back. Photo via the BBS.


This was the case in 2007 when Joe Whelan sued the Andy Warhol authenticating body claiming that they had twice rejected an authentic work by the Pop artist. Just years later, the Warhol Foundation stopped authenticating works due to mounting legal fees. Soon, other foundations followed suit, opting to stay out of the authentication fray entirely to avoid costly legal battles.

In 2016, Tad Smith, then the CEO of Sotheby’s, was candid about the financial cost of authentication issues. “If you looked at earnings reports from a year or two ago,” Smith remarked, “you’d see little blips here and there. There were expenses coming from settlements – not a slew, the number was small and statistically insignificant, but they’re expensive.”

How to gain traction in the art of authentication

While the prognosis for authentication sounds bleak, all hope is not lost. In fact, as the art world has recognized issues around authentication and those experts have sought out protection from larger organizations, there have been developments that are gaining credence.

Example of when X-ray is used on an artwork, this time in Artemisia Gentileschi’s 1619 “Saint Catherine of Alexandria.”

One of the biggest developments is in technology. Researchers and conservators now have incredibly high-tech instruments at their fingertips that help determine if an artwork could have been made by an artist. X-rays have long been a part of how researchers could see beneath a painting. This could tell you if there were any underdrawings or grid work, which would add to the biography of the artwork. Sometimes, an X-ray is all it takes to find that an artwork is fake. Imagine looking beneath the surface of a Pollock and find what looks to be a work by Piet Mondrian!

Microscopes have advanced a great deal in recent years, allowing for greater study of the surface of a work as well as the components it’s made up of. Fourier-transform infrared spectroscopy allows a researcher to get a snapshot of the molecular makeup of an artwork and the materials used in it. This can tell a researcher if the work was made at a particular time or if the elements in it were available when it was supposedly produced—a strategy which brought down noted forger Wolfgang Beltracchi.

To develop an the most holistic understanding of a given work, experts also use multispectral and hyperspectral infrared imaging alongside infrared spectroscopy.

These, of course, are costly examinations and so, they aren’t something that can be done to every artwork. However, when lower-tech instruments don’t suffice – just looking at the surface of an artwork with a beam of light sweeping across it can tell so much – the big guns, so to speak, can be brought out.

Despite the problems affecting the art authentication industry, it’s also producing some shining stars, such as James Martin—who’s become one of the art world’s most trusted researchers and conservators. His company, Orion Analytical, was one of the only companies that did the style of forensic analysis needed to better understand artworks. Instead of relying on the subjective expertise which proved so controversial in the La Belle Ferronière trial, Martin relied on hard science. Now, Martin works with Sotheby’s, who absorbed Orion Analytical in 2016—becoming the first auction house to have an internal conservation science lab service.

The move helped Sotheby’s, which, as former CEO Tad Smith highlighted, was keen to fight against cases of art fraud—in a high-profile case dating from 2010, the auction house sold a painting attributed to Dutch old master Frans Hals which ended up being a forgery. The partnership also helped protect Martin—who, a few years before joining forces with Sotheby’s, had worked on a major case which landed him in the hot seat.

Ann Freedman and her defense team during the Knoedler hearings. Illustration by Victor Juhasz.

In 2011, the Knoedler Gallery closed its doors somewhat unexpectedly. The gallery was one of New York’s most prestigious galleries and at the time, had more than 160 years of business under its belt. The stunning reason for the closure was the revelation that, for years, the gallery had been engaged in the trafficking of counterfeit artworks—some 40 illicit paintings passed through its doors. Between 1994 and 2008, the gallery seemed to do well under the guidance of Ann Freedman, but in the background, a forgery ring was in the works that would yield $80 million during its time.

Enter James Martin, who was called in to examine a number of paintings thought to be forgeries and found them not to be authentic. During the trial, Martin was raked through the mud but ultimately, his findings were supported by the FBI. After that, though, Martin was shell-shocked from the whole ordeal. So, when Sotheby’s offered to support him, it came with backing needed in today’s authentication field.

Not every authenticator, though, is able to go into business with larger auction houses. That’s when other organisations, like the International Foundation for Art Research (IFRA) and the International Catalogue Raisonné Association (ICRA), come into play. Both organisations work to help cover the bases for authenticators so that they aren’t intimidated by disappointed collectors. The IFRA, founded in 1969, has resources in tools that can help experts get to the bottom of an artwork’s past. However, the association is limited as it can only work with a finite number of artworks at once. The ICRA, on the other hand, was founded just last summer in conjunction with the Royal Academy in London. Its goal is to “support the production of definitive inventories of an artist’s accepted artworks.” The non-profit also assists experts in the form of discounted legal services and legal advice.

Art authentication remains essential

This help is essential to mitigating the pressure which lawsuits and threatening collectors can place on art authenticators and the authentication process. And that’s something that’s critical given how important the continued input of authenticators will always be to the art world. While forgers get more talented, so will the mechanisms in place to stop them but in the meantime, the grey side of the art market is booming.

Here, we will let Pierre Valentine, the founder of the ICRA, have the last word as we look forward to what is to come in the world of fakes, forgeries, misattributions, and authentication: “At a time when authenticity committees are closing down, and experts are being threatened and becoming concerned about expressing an opinion for fear of retaliation, it is really important that scholars and experts have a place where they can feel free to talk, discuss and share.”