Mark Geffriaud strives to obscure the clues of the individual artist’s signature by inviting friends, critics, designers, and other artists to collaborate on his work. For his recent double exhibition at the École Municipale des Beaux-Arts in Gennevilliers (“Et Mason”) and at the Zoo Galerie in Nantes (“Et Dixon”), he was joined by no fewer than ten people (and had invited a hundred). Artist and photographer Aurélien Mole shot portraits of Geffriaud’s collection of preparatory source images, extracted from books, magazines, and journals, which were then printed as panoramas along one wall in