Peter Alexander in 1966. Image courtesy of and © Billy Al Bengston

Helen Pashgian polishing one of her sculptures in the Baxter Art Gallery at the California Institute of Technology in Pasedena for an artists in residence exhibition, 1970. Courtesy of and © Helen Pashgian

Announcement for Frederick Eversley exhibition Colored Parabolic Space at the Quay Gallery in San Francisco, 1971. © Frederick Eversley. The Getty Research Institute, Gift of George Herms, 2009.M.20

Rani Singh of the Getty Research Institute and Jack Brogan, conservator, inspect De Wain Valentine's Red Concave Circle in Brogan's studio in Inglewood, California, June 17, 2011. © De Wain Valentine

Two Gray Walls, 1975–76, De Wain Valentine. Cast polyester resin. © De Wain Valentine. Photo courtesy of De Wain Valentine

Larry Bell’s studio in 1970. Photo by Larry Bell. Image courtesy of Billy Al Bengston

Slideshow: De Wain Valentine’s process of creating Gray Column, 1975–76. © De Wain Valentine. First, 4th, 5th, 6th, and 8th photo by and © Cathy Weiner; 2nd and 3rd photo by Sean Valentine

De Wain Valentine and two of his studio assistants, Chris D'Arcangelo (left) and Keith Anderson (right), 1975–76. Photo © Cathy Weiner

Slideshow: Gray Column moves from conservator Jack Brogan’s studio to the J. Paul Getty Museum, 2011. Artwork © De Wain Valentine

Slideshow: Documentation of De Wain Valentine‘s Circle series of polyester resin circles, 1960s. Artwork © De Wain Valentine. Photo © Harry Drinkwater

De Wain Valentine in his Venice studio. Photo: © Cathy Weiner

De Wain Valentine in his Venice studio with one of his eight-foot Circle polyester pieces, 1970s. Artwork © De Wain Valentine. Photo © Harry Drinkwater

De Wain Valentine polishing Gray Column in 1976. © De Wain Valentine. Photo courtesy of De Wain Valentine

De Wain Valentine in front of Gray Column, 1975–76, during the polishing stage. © De Wain Valentine. Photo courtesy of De Wain Valentine

Mary Corse working in downtown Los Angeles in 1966. Image courtesy of and © Mary Corse