Donald Judd lauded the straightforward simplicity of three-dimensional geometrical objects, and avoided illusionism in his work. Still, he appreciated the allure of color, and in 1964 he began to use colored Plexiglas as a medium. Plexiglas appealed to the artist because its color is intrinsic to its material, not added later or painted on. Judd, whose interest in the natural world figured in his relocation in the 1970s from New York City to West Texas, always preferred the honesty of natural light on his works, and often chose to exhibit his sculpture near natural light sources.