Robert Irwin. Layout Gallery 3/Four Corners-Room/Black-Window Indication, Walker Art Center, Minneapolis, 1976, 1977. Pen and ink, collage, and transfer type on paper, Sheet: 30 1/16 × 35in. (76.4 × 88.9 cm). Whitney Museum of American Art, New York; gift of the artist, 77.52. ©Robert Irwen/Artists Rights Society (ARS), New York (Photo: Whitney Museum of American Art)