Untitled, 1952, John McLaughlin. Oil and casein on fiberboard. 32 1/8 x 48 1/8 in. Hirshhorn Museum and Sculpture Garden, Smithsonian Institution, Washington, D.C., Joseph H. Hirshhorn Purchase Fund, 1991. Photographer: Lee Stalsworth

Untitled, 1970, Frederick Eversley. Three-color, three-layer cast polyester. 20 x 20 x 6 in. Collection of the artist. © Frederick Eversley

Untitled, 1967, Robert Graham. Polyurethane resin. 8 5/16 x 11 7/16 x 11 1/8 in. Collection of Ed Ruscha. © Estate of Robert Graham

Untitled, 1969, Larry Bell. Mineral-coated glass. 40 x 40 x 40 in. Courtesy The Pace Gallery. © Larry Bell. Photo by Ellen Labenski

Untitled, 1969, Helen Pashgian. Cast sphere, color polyester resin. 7 in. diam. Norton Simon Museum, Gift of the artist. © Helen Pashgian

Untitled, 1966, Noah Purifoy. Mixed media, including debris from the Watts rebellion. 29 3/4 x 16 3/16 in. Private collection. Permission granted by the Noah Purifoy Foundation

Untitled, 1959, Henry Takemoto. Stoneware with iron and cobalt brushwork. 26 3/4 x 27 3/4 in. Collection of Pier Voulkos. © Henry Takemoto. Photo by Joe Schopplein

Untitled (Faceless Faces with Kabala), 1963–70, Wallace Berman. Verifax collage with transfer lettering. 29 7/8 x 28 11/16 in. Collection of Nicole Klagsbrun. Permission courtesy of the Estate of Wallace Berman and Michael Kohn Gallery, Los Angeles

Untitled (Leaner), 1970, Peter Alexander. Polyester resin. 104 ½ x 5 ½ x 3 in. Collection of the artist. © Peter Alexander

Untitled (Portrait of Crystal), ca. 1961, Marjorie Cameron. Ink and gouache on wood panel. 43 1/2 x 11 3/4 in. Collection of Scott Hobbs. Permission courtesy of Cameron Parons Foundation

Untitled (Red on White Optical), 1964, Lorser Feitelson. Oil on canvas. 60 x 40 in. Courtesy of D. Wigmore Fine Art, Inc., New York. Image © Feitelson Arts Foundation, courtesy Louis Stern Fine Arts. © Photo by Casey Brown

Untitled (Venice), 1967, Lee Mullican. Oil on canvas. 80 x 120 in. Estate of Lee Mullican, Courtesy of Marc Selwyn Fine Art, Los Angeles. © Estate of Lee Mullican

Untitled (Verifax Collage), 1969, Wallace Berman. Verifax collage on board. 45 x 48 in. Collection of Michael D. Fox, Berkeley, CA, courtesy Steven Wolf Fine Arts, San Francisco, CA. Permission courtesy of the Estate of Wallace Berman and Michael Kohn Gallery, Los Angeles. Photo by Joe Schopplein

Untitled (White Light Grid Series-V), 1969, Mary Corse. Glass microspheres in acrylic on canvas. 108 x 108 in. Andrea Nasher Collection. Permission courtesy Ace Gallery and the artist

Untitled, Wall Piece, 1967, Larry Bell. White and black glass, vacuum coated. 120 x 300 in. Collection of Michael Straus, Birmingham, Alabama. © Larry Bell