Mies van der Rohe, Ludwig. IIT Library and Administration Building, Chicago, Illinois, Window frame. Perspective. Structural details. Sections., 1944. Pencil on Apex note paper, 6 x 8 1/2" (15.2 x 21.6 cm). Mies van der Rohe Archive, gift of the architect
, MR4404.180. (Photo: MoMA)