In 1967, he designed the set and costumes for Scramble, a dance piece by Merce Cunningham. The Museum of Modern Art in New York presented a retrospective of Stella's work in 1970, making him the youngest artist to receive one. During the following decade, Stella introduced relief into his art, which he came to call "maximalist" painting for its sculptural qualities. The shaped canvases took on even less regular forms in the "Eccentric Polygon" series, and elements of collage were introduced, pieces of canvas being pasted onto plywood, for example. His work also became more three-dimensional to the point where he started producing large, free-standing metal pieces, which, although they are painted upon, might well be considered sculpture. After introducing wood and other materials in the Polish Village series (73), created in high relief, he began to use aluminum as the primary support for his paintings. As the 1970s and 1980s progressed, these became more elaborate and exuberant. Indeed, his earlier Minimalism became baroque, marked by curving forms, Day-Glo colors, and scrawled brushstrokes. Similarly, his prints of these decades combined various printmaking and drawing techniques. In 1973, he had a print studio installed in his New York house. In 1976, Stella was commissioned by BMW to paint a BMW 3.0 CSL for the second installment in the BMW Art Car Project. He has said of this project, "The starting point for the art cars was racing livery. In the old days there used to be a tradition of identifying a car with its country by color. Now they get a number and they get advertising. It's a paint job, one way or another. The idea for mine was that it's from a drawing on graph paper. The graph paper is what it is, a graph, but when it's morphed over the car's forms it becomes interesting, and adapting the drawing to the racing car's forms is interesting. Theoretically it's like painting on a shaped canvas."