Sam Gilliam’s Half Circle Red combines separate pieces of canvas, which gap, bulge, and double over. Without a traditional mount or frame, they are pinned in place directly to the wall. Interested in how his paintings interact with the surrounding space, Gilliam jettisoned stretchers—typically wooden rectangular support structures—altogether during the late 1960s. Instead, his relaxed, undulating canvases suspend from the wall or ceiling to create “drape” paintings. This method, along with his drip and stain painting technique, emphasized the intrinsic properties of his materials—how acrylic pools and canvas sags, for example.