The Isabella Stewart Gardner Museum, vexed for decades by one of the art world’s most dramatic mysteries, cracked a case of less but still some significance when conservators identified the original fabric for a set of chairs in need of restoration in the museum’s Dutch Room—the site of the greatest art heist of all time.That mystery derives from the still unsolved case of three invaluable paintings—by Vermeer, Rembrandt, and Manet—that were stolen by thieves who broke into the Dutch Room in 1990 and made off with artworks whose whereabouts remain unknown. The newer mystery involves the question of how best to spruce up a set of 17th-century chairs to a period-faithful state as part of a three-year restoration of the Dutch Room.As reported by the Boston radio station WBUR, “Much of its restoration has consisted of relatively straightforward tasks, like cleaning the painted Italian ceiling and refinishing the floors. But the set of 14 chairs posed a unique challenge. They had been reupholstered multiple times over the years, and the old fabric was lost.”Anna Rose Keefe, the Gardner Museum’s textile conservator, has kept archival photographs and fabric samples on bulletin boards likened to those stared down by hardscrabble police investigators puzzling out inferences and connections. “A lot of the visuals around this feel very Law and Order to me,” she told WBUR.Speaking of the museum’s founder, Isabella Stewart Gardner, director of conservation Holly Salmon said, “ In a project like this, we try to really think about what she intended us to see.”In the case of the chairs, that was striped-pattern upholstery that differed from the fabric that had covered them since the 1970s. But the original color was not evident in black-and-white photographs, so the conservators turned to Palette, an AI software platform that colorizes old pictures. Findings of that plus the discovery of a tiny piece of faded thread confirmed conjecture that the chairs had originally been red—with pink stripes interspersed.Now the chairs have been reupholstered to their more vibrant state. Again referring to Gardner herself, Keefe, the textile conservator, said, “She likes a silk that’s really shiny. She likes something that’s really going to pop in the space.”As for the rest of the Dutch Room, home to Rembrandt’s Self-Portrait, Age 23, restoration is expected to be complete by early 2027—at which point, according to the Gardner’s website, “young Rembrandt will look out over a room beautifully restored, much closer to Isabella’s original vision, and ready to welcome back the stolen works when they someday return (we hope and believe) to their rightful home.”