Varese Scrim, 1973. Nylon scrim, dimensions site-determined; room: 150 3/8 x 563 x 72 1/6 inches; scrim: 150 3/8 x 563 inches. Solomon R. Guggenheim Museum, New York. Panza Collection, Gift, on permanent loan to Fondo per l'Ambiente Italiano. 92.4134 Robert Irwin has consistently deemphasized the making of objects, focusing instead on an awareness of perceptual phenomena. Irwin started out as a painter but eventually abandoned the canvas and its finite edges, striving instead to incorporate his art with the space around it. In 1966 he completed the first of his discs, circular forms made of aluminum. These pieces, which are attached to the wall and lit with flood lights, meld object, shadows, and architecture into one coherent expanse. Since the 1970s Irwin has focused on the site itself by creating installations in rooms, gardens, parks, museums, and various urban locales. These interventions, constructed with materials such as scrim and fluorescent lighting, manipulate and draw attention to the optical conditions of the environment and how we perceive these conditions through subtle, sometimes imperceptible alterations of scale, light, volume, and atmosphere. Irwin's installations, such as Soft Wall, direct attention to those transient and seemingly incidental elements in our field of observation. Soft Wall—originally installed at the Pace Gallery, New York, in 1974—is a significant work in Irwin's oeuvre and expresses his interest in reevaluating conceptions of space, presence, and emptiness. Here, Irwin has dematerialized the structure of a wall to almost nothing, confounding our expectations of the familiar.