Photo fraud: eBay to the rescue!

In the 1990s the market for photos exploded. As snapshots started selling for millions of dollars, sham photos also slipped into the fray before the art world had any way to authenticate originals. And so cultural heritage researchers had to play some serious catch-up, and quickly. That’s the gist of my recent cover story on photo conservation. It explores how two fraud cases helped turn the field from a niche research area to a mature science. And as always happens when reporting, many cool tidbits didn’t fit in to the final piece… In this case, the pivotal role eBay played to help researchers develop ways to catch fakes. But first, a bit of background on photo fraud: In the photo market, people will pay more money for an image when it was actually printed on paper by the photographer himself or herself. The price can also increase when the print is older. So, for example, the Getty Conservation Institute’s Art Kaplan told me that an Ansel Adams photograph printed in the 1920s can sell for hundreds of thousands of dollars, while the exact same photograph printed a few decades later (say, the 1970s) can sell for just tens of thousands of dollars. It turns out that researchers wanting to authenticate a photo spend a lot of time scrutinizing the paper on which it has been printed, because photo paper generally provides the best dating and provenance clues. For example, researchers look for chemicals called optical brighteners which were added to all photo paper to brighten images starting in the 1950s. If a photo is purported to have been made earlier than the 1950s, then it can’t have any optical brighteners in the photo paper. Likewise, in the 1880s, companies started adding a so-called baryta layer to the top of photo paper as a physical barrier between image and paper, so trace impurities in the paper wouldn’t leach into the image layer and wreck the picture. Each company used a different ratio of barium and strontium in the baryta layer, and companies also changed these ratios over time. Since most photographers were loyal to a particular photo paper brand, authenticators check to see whether a suspect photo has barium and strontium ratios that correspond to the photographer’s preferred company during the era when the photograph was supposedly printed. Of course to make these comparisons, you need an enormous database of reference photo paper, says Paul Messier, a photograph conservator who helped develop ways to authenticate Lewis Hine prints in one of the world’s first million-dollar photo fraud cases. “A switch flipped on when I was working on the Hine project,” Messier says. “I...

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A Fun Video About Photo Conservation And The History of Photo-making

Earlier this year, I had the opportunity to visit the Getty Conservation Institute with videographer Kirk Zamieroski. This is a cool video he made about the photo conservation research that takes place in the GCI’s Los Angeles laboratories. It features the GCI’s Art Kaplan talking about a few of the 100+ different photo-making processes (wowsers!) used since the dawn of photography. Enjoy! PS:  ….And if you want to know why some old photos have a brownish “sepia” look, check out this piece about the research of GCI’s Dusan Stulik and Tram...

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Mercury In Platinum Prints Makes Things Sepia–Or Does It?

Around 1889, Gertrude Käsebier, a 37-year-old, unhappily married mother of three, decided to go to art school. A decade later, around 1900, Käsebier’s photo studio in New York City was so successful that her platinum print portraits were “the thing to have,” in turn-of-the-century socialite circles, says Tram M. Vo, an independent conservator who has been collaborating with Dusan Stulik at the Getty Conservation Institute. “At the time, photographers charged about $12 for 12 prints,” Vo says. “Käsebier charged people $25 just to sit for a photograph and $5 for a single print.” There’s not a lot known about Käsebier’s techniques in the dark room because she didn’t leave many notes behind. So Vo is trying to learn about her methods using an analytical technique called X-ray fluorescence spectrometry (XRF). Conservation scientists use XRF to get a list of the chemical elements present in an artwork using X-rays—all without touching or destroying the artwork. In particular, Vo wants to learn more about the so-called sepia look in many of Käsebier’s prints. Sepia is the word used to describe when black and white photographs have a brownish tint that gives the shots a warm feeling. In today’s digital world, giving a photo a sepia look is just a Photoshop click away. But when Käsebier wanted to give her platinum prints the sepia look she had to use dark room chemistry. Photo history experts have long thought that if a photo from that era had a sepia look, it probably came by means of a few drops of a mercury bichloride, added during the development process. Vo is finding that this might not always be true. Vo used the XRF to look at the elements in Käsebier’s sepia-looking photographs. She found that some of Käsebier’s sepia prints had no mercury present, and thus the warm tones must have come from a different process—but what? It’s possible that Käsebier sometimes got the sepia look from iron found in development solutions, Vo says. Normally the iron would be rinsed off the print during the development process, but if the iron was left behind, it could break down cellulose in the paper over time, which would add a sepia tinge to the prints. Vo also used XRF to look at Käsebier photographs that didn’t have the sepia look, and was surprised to find mercury on non-sepia black and white prints. Käsebier must have used mercury in other dark room processes, but it’s not clear yet which ones. Obviously there’s more fun photo-forensic work left to be done to completely understand Käsebier’s techniques. Even though Käsebier used mercury regularly in the darkroom, which is not precisely the...

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Using A Digital Light Projector To Restore Mark Rothko Paintings

One of the coolest talks I saw at the ICOM-CC conference in Lisbon last week came from Jens Stenger, a conservation scientist at the Harvard Art Museums in Boston. He had the tricky task of figuring out what to do about five paintings by Mark Rothko in the museum’s collection that were so damaged from sunlight exposure that crimson paint on the canvas had turned to blue. If just a tiny corner of the paintings were light damaged, museum staff might have considered retouching the artwork with a little paint. But a massive fraction of the massive panels were seriously light-damaged. And these days the trend in art conservation is to minimize interventions on art, especially contemporary art. So a team of curators, conservators and scientists decided that, “repainting was NOT the way to go,” Stenger said. But everyone thought museum visitors would want to know how the artwork had looked before the light damage. So what to do? The solution Stenger came up with is pretty cool: Figure out the exact coloration of the originals. Display the artwork as is, but set up a digital light projector that can cast an image on to the canvases. This projected image temporarily makes the paintings appear as they did when Rothko finished them in 1963. Switch off the projector and the paintings are returned to their current-day states. It’s effectively restoration with an undo button. (And as an aside, the amount of light delivered by the projector is not sufficient to continue to harm the painting.) But like most things in life, this seemingly simple solution took a lot of work. First off, Stenger wanted to know more about why the paintings had faded so dramatically. In 1988 Paul Whitmore reported that the fading crimson red paint in the Rothko paintings had been a synthetic pigment called Lithol red mixed in with a bit of ultramarine blue. Lithol red is a problematic pigment to begin with, Stenger said, but the fading due to the excessive sunlight exposure was probably exacerbated by the fact that Rothko mixed the red with ultramarine blue. It turns out ultramarine blue can also catalyze bleaching of Lithol red. Next up, Stenger looked for photographs of the original paintings, so that the team knew exactly the colors in the painting before fading. This way they could project the right color of light on to the old canvases. Luckily, color film ektachrome images of the Rothko canvases had been taken in 1963, Stenger said. The bad news is that some of the blue pigments in the ektachromes had faded, distorting the colors in the ektachrome image so...

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