Guy Morin, the mayor of Basel, acknowledged news of the sale of the Gauguin and bemoaned its loss. On Tuesday, The Baer Faxt, an art world insiders’ newsletter, said Qatar was rumored to be the buyer of the Gauguin at $300 million, which would exceed the more than $250 million that Qatar reportedly paid for Paul Cézanne’s “The Card Players” in 2011. 
 
 Todd Levin, a New York art adviser, said of the Gauguin, “I heard that this painting was in play late last year.” He added, “The price quoted to me at that time was in the high $200 millions, close to $300 million.” 
 
 In recent years the Qatar royal family and the museums authority have been reported to be expansive buyers of trophy quality Western modern and contemporary art by Mark Rothko, Damien Hirst and Cézanne. In a move that jolted Basel as news of the sale trickled out, Mr. Staechelin said that his family’s trust was ending its loan to the Kunstmuseum as a result of a dispute with the local canton. He said that he was searching for a top museum to accept the Staechelin collection — which also includes works by van Gogh, Picasso and Pissarro — on loan, without a lending fee, with a promise to integrate the pieces into permanent exhibitions. 
 
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 The works were amassed by his grandfather, a Swiss merchant also named Rudolf Staechelin, who befriended artists and made most of his purchases during and after World War I. Later, the elder Mr. Staechelin advised the Kunstmuseum, which accepted the loan of his collection after his death in 1946. 
 
 The grandson said that the works had never been hung in his family’s home because they were too precious and that he saw them in a museum along with everyone else. He has decided to sell, he said, because it is the time in his life to diversify his assets. “In a way it’s sad,” he said, “but on the other hand, it’s a fact of life. Private collections are like private persons. They don’t live forever.” 
 
 On the last few days before closing last weekend for renovations through 2016, the Kunstmuseum opened its doors for free and drew a record crowd of 7,500 people, many of whom caught the last glimpse of the Gauguin in its longtime home. 
 
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 Gauguin’s Tahiti-period paintings are among the most admired and coveted artworks of the Post-Impressionist period. This particular piece, focusing on the enigmatic interplay between two girls in a Polynesian landscape, was painted during the first of the artist’s two spells living in Tahiti. 
 
 The painting will still be on display at a special Gauguin exhibition opening this month in Basel at the Beyeler Foundation and then the collection will travel to the Reina Sofía museum in Madrid and the Phillips Collection in Washington. The buyer will take ownership next January, Mr. Staechelin said. 
 
 Local institutions in Basel, which learned definitively about the loss of the collection on Thursday morning, were still trying to come to grips with the news. The Kunstmuseum issued a brief statement about the loss saying, in part, “We are painfully reminded that permanent loans are still loans.” 
 
 Mr. Morin, the mayor, said in a statement that the canton tried to persuade Mr. Staechelin to bring back the collection when the museum reopened in April 2016. But for months the canton and the family trust squabbled behind the scenes over an existing loan contract. 
 
 Mr. Staechelin said that he had sought a new contract after the museum announced plans to shut down. When canton officials failed to budge on a new contract, he said, he canceled the existing one because of a provision that requires that the artworks be on public display. 
 
 “The real question is why only now?” Mr. Staechelin said of the Gauguin sale. “It’s mainly because we got a good offer. The market is very high and who knows what it will be in 10 years. I always tried to keep as much together as I could.” He added, “Over 90 percent of our assets are paintings hanging for free in the museum.” 
 
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 “For me they are family history and art,” he said of the artworks. “But they are also security and investments.” 
 
 James Roundell, a director at the London dealership Simon Dickinson, said that in the roiling global art market, “a new category of super trophy is emerging.” 
 
 “These items are generally in museums and they’re being sold privately, which explains the very high prices,” he said. “If they were offered at auction, would there be competition at that level?” ||||| French artist Paul Gauguin is well known for his colorful paintings of Tahitian life -- such as the painting that sold recently for nearly $300 million -- but he also was a highly experimental printmaker. Little is known, however, about the techniques and materials Gauguin used to create his unusual and complex graphic works. 
 
 Now a team of scientists and art conservators from Northwestern University and the Art Institute of Chicago has used a simple light bulb, an SLR camera and computational power to uncover new details of Gauguin's printmaking process -- how he formed, layered and re-used imagery to make 19 unique graphic works in the Art Institute's collection. 
 
 Northwestern computer scientist Oliver S. Cossairt will provide a surprising new explanation of how Gauguin created one of these artworks Saturday, Feb. 14, at the American Association for the Advancement of Science (AAAS) annual meeting in San Jose. It will be the first report of the Northwestern-Art Institute study of the 3-D surface of the print "Nativity (Mother and Child Surrounded by Five Figures)," made by Gauguin in 1902. 
 
 Cossairt's talk, "Surface-Shape Studies of Gauguin's Monotypes," will be part of the AAAS symposium "Worth More Than a Thousand Words: State-of-the-Art Visualization in Cultural Heritage" to be held from 8:30 to 11:30 a.m. PST in Room LL21E of the San Jose Convention Center. Co-organized by Northwestern and the Art Institute, the symposium will feature international experts from universities, museums and industry with a focus on using computation and imaging to analyze valuable artworks noninvasively. 
 
 The new results establish Gauguin's use of materials and process in a chronological order, solving the puzzle of how "Nativity" was made. Gauguin created the print using a layering of images created on paper by drawings, transfer of images and two different inks. The surface topography research on "Nativity" and other graphic works by the artist will be part of a major Gauguin exhibit at the Art Institute in 2017. 
 
 The "Nativity" findings overturn an earlier theory as to how Gauguin might have produced the print. Cossairt's art conservator colleagues initially were "blown away" by the scientific results, so the research team reproduced, in an Art Institute lab, what they believed to be Gauguin's process. The printmaking process the research team had identified produced a print very similar to Gauguin's original. 
 
 "To measure the 3-D surface of the prints, we used some very accessible techniques that can be used by art conservators and historians around the world to analyze artworks," said Cossairt, who developed the software to analyze the imaging data. "In applying these techniques to Gauguin's work, we came up with some interesting answers to questions about what his printing process was." 
 
 Cossairt is the Lisa Wissner-Slivka and Benjamin Slivka Junior Professor of Computer Science at Northwestern's McCormick School of Engineering and Applied Science. 
 
 Cossairt and his colleagues studied "Nativity" and 18 other Gauguin monoprints in the Art Institute's collection. They used multiple wavelengths of light shining from different directions onto the prints to investigate the surface of the paper and reevaluate how Gauguin created his works. The photometric stereo technique allowed the researchers to mathematically separate color from surface shape, providing a much clearer view of the paper's topography. 
 
 For the study of an artwork, the piece was fixed in place, as was an SLR camera. A light bulb was moved to 20 different locations and a photo taken of the artwork for each light bulb position. The digital data for each pixel of each image then was run through Cossairt's software. Essentially, the researchers were measuring only the response of an artwork's surface to changing lighting. (Each digital image is 10 megapixels, meaning the researchers processed 20 million pixels for each artwork.) 
 
 "The technique allows us to peel away the print's color and look at the surface structure only," Cossairt said. "For each image, we know the angle of the lighting and the brightness of each pixel and from that we can calculate the unknown -- the surface structure." 
 
 The surface structure of "Nativity" revealed solid evidence of two new things: 
 
 * The white lines, in which there is an absence of ink (they have been known as "blind incisions"), are on a flat surface. This indicates those lines were not produced using a relief process but rather a transfer process, where Gauguin drew on an inked surface, removing ink, and those empty lines were transferred to his print. 
 
 * The ink of the black lines sits atop ridges in the paper, indicating a monotype transfer process was used. Gauguin would have placed his paper on an inked surface and then drawn on the back of the paper, causing ink to be transferred to the paper where pressure from the artist's pencil was applied. (The pressure also caused the ridges.) 
 
 For some of Gauguin's work, his technique is clear and unambiguous -- a straightforward oil painting or woodblock print. But for other works, it is difficult to understand his process of creation. Art Institute conservators and historians couldn't ask Gauguin about his techniques, so one year ago they turned to collaborators at Northwestern for help finding some answers. 
 
 "Gauguin died more than a century ago, but there is still something to say, something new to find out, in large part due to this teamwork," said Harriet Stratis, senior research conservator at the Art Institute and the museum's lead collaborator on the Gauguin project. 
 
 "We never would have figured this out without Northwestern, its scientists and technology, because you don't see the evidence under the microscope," Stratis said. "You can't tell the paper is just flat. The Northwestern team's lighting and imaging techniques show there is no deformation in the paper where the un-inked lines are, which blew me away. 
 
 "Gauguin probably was doing these kinds of prints for five years, so this research puts a whole body of work together," she said. "The evidence points to a completely different artistic approach by Gauguin." 
 
 This cutting-edge collaborative work was made possible through the Northwestern University-Art Institute of Chicago Center for Scientific Studies in the Arts (NU-ACCESS). 
 
 Led by Marc Walton, its senior scientist and a key collaborator on the Gauguin project, the center's mission is to provide scientific support for the investigation of art collections, as well as to develop new technology to look at art, such as the photometric stereo technique and software used by Cossairt. 
 
 "Gauguin made thousands of prints -- it often was his way of working through ideas for his colorful paintings," said Walton, co-organizer of the "Worth More Than a Thousand Words" AAAS symposium. 
 
 "By studying this one unique piece, 'Nativity,' we are developing a deeper understanding of Gauguin's highly experimental printmaking and transfer techniques that we can apply to his other works, including his paintings," he said. 
 
 The Gauguin study is just one of many collaborative projects taking place within NU-ACCESS. The center, a national model of interdisciplinary scientific research in the arts established in 2012 with support from the Andrew W. Mellon Foundation, grew out of a fruitful research partnership between Northwestern and the Art Institute. 
 
 "At the center, we are interested in determining who had access to various technologies at different time periods and how they innovated to achieve alternatives or improve on existing processes," Walton said. 
 
 "We then can use this knowledge for devising conservation treatments, for determining the provenance of objects and sometimes for authentication," he said, "but it ultimately comes back to the idea of how do people innovate and evolve? In the case of Gauguin, we are truly understanding his creative process through the application of these imaging techniques." 
 
 ### ||||| A group from Northwestern University and the Art Institute of Chicago has been using computer imaging tools to uncover details about Paul Gauguin’s artistic process. Even though there is a vast amount of scholarship on the French Impressionist painter, who died in 1903, there has been little information about his printmaking technique until now. 
 
 The people behind the project may seem like an unlikely combination—computer scientists and art conservation specialists. Northwestern assistant professor Oliver Cossairt announced the findings Saturday at an American Association for the Advancement of Science meeting. Cossairt concedes that he knew little about Gauguin before last fall, but he and his colleagues realized the potential for bringing their expertise into the museum setting. 
 
 Beginning last September, the team has been capturing data about 19 Gauguin prints housed at the Art Institute. The project’s most in-depth analysis so far has focused on Nativity (Mother and Child Surrounded by Five Figures) from 1902. Gloria Groom, senior curator of 19th-century European painting at the Art Institute, says art scholars never thought it possible to explore the miniscule markings on the surfaces of such prints, which appear much flatter than richly layered paintings. “We think of a print as, that’s it. That’s all you get,” Groom says. “We never knew how we could extract this other information.” 
 
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 While Gauguin is better known for his late 19th-century paintings—one of which reportedly sold for $300 million, believed to be one of the highest prices ever paid for an artwork, a little more than a week ago—he experimented with innovative printmaking techniques in the last years of his life. “They’ve been thought to be one way and now we’re finding out they’re much more complicated,” Groom says about the prints. 
 
 The Northwestern and Art Institute people focused on that technique and sought to figure out how exactly Gauguin crafted his intricate lines. They used photometric stereo, a process that dates to the 1980s and involves taking a sequence of photographs from a fixed camera location while shining a light on the subject. Between taking photographs, the light moves to a new position. For this project, the scientists can use the shifting light “to mathematically separate color from surface shape, providing a much clearer view of the paper's topography,” according to a press release. 
 
 The Art Institute of Chicago, Gift of Robert Allerton 
 
 “We just used very simple, inexpensive components, and it can be replicated by any conservator or conservation scientist working at any museum,” Cossairt says. It’s an accessible method, but still labor intensive; the team processed 20 million pixels for each print. 
 
 The team uncovered precisely how Gauguin layered his lines for Nativity; the scientists even used their calculations to re-create the work. Some findings were previously unknown to art experts, such as how the artist achieved certain types of lines, and they indicated that a “monotype” printmaking process was used. 
 
 The Art Institute will incorporate the findings into an upcoming online catalog on Gauguin and a 2017 exhibition that will eventually travel to the Musée d’Orsay in Paris. 
 
 Nativity depicts a woman at the center holding an infant; they each have halos around their heads. Beside and behind them are five additional figures. Groom says Gauguin turned to monoprinting upon returning to Tahiti for the second time in his life. Unlike the artist’s more well-known works, in which Gauguin depicted subjects from his daily life, he was more distanced from the subjects of the monoprints, Groom says. Nativity is dated 1902, only one year before the artist’s death. 
 
 “For Gauguin scholarship, it’s just one more chapter,” Groom says of the Northwestern project. “I think people are so akin to seeing the paintings,” she adds. “The one thing that never gets the full amount of attention is his work on paper, which is so radical.”
– The French artist Paul Gauguin may be best known for his paintings—one of which sold just this month for $300 million, one of the highest prices ever paid for a work of art—but the printmaking he worked on toward the end of his life in the early 1900s is turning out to be so complicated and experimental that art conservators are "blown away" by the new findings, reports Northwestern University. Computer scientist Oliver S. Cossairt, who announced the findings in San Jose over the weekend, worked with art conservation specialists at the Art Institute of Chicago to reveal Gauguin's surprising techniques, including layering, transferring, and re-using imagery. Since September, the team has been analyzing 19 of the artist's prints at the Art Institute—the most in-depth analysis being of the work "Nativity (Mother and Child Surrounded by Five Figures)," completed in 1902 a year before Gauguin's death—using a process that dates back to the 1980s called photometric stereo. It entails taking a sequence of photos from a fixed camera while light on the subject jumps to a new position. Software then helps separate out color from surface shape to detail the paper's topography. Cossairt tells Newsweek the process is "simple" but still "labor intensive," with 20 million pixels processed for each print. One finding: Gauguin made white lines by drawing on an ink surface, thereby removing the ink, and transferred the resulting lines to the print. (Check out why one woman attacked a Gauguin painting in Washington's National Gallery.)