How do you make a documentary about someone who’s taken pains to remain out of the spotlight? Alison Chernick set out to do just that. Known for her documentaries on Jeff Koons, Matthew Barney, and Roy Lichtenstein, the filmmaker had never addressed the world of fashion in her work. But for her new short documentary, The Artist Is Absent — premiering tomorrow at the Tribeca Film Festival — she took on easily the most elusive subject in fashion:Martin Margiela. The film will also premiere on Yoox, the Corner, and Shoescribe on April 27. In advance of the premiere, Chernick talked to the Cut about making the crossover from art to fashion and the challenges of directing a documentary about one of the least-documented public figures out there.