Zig was Smiths abbreviation of Ziggurat, after the terraced pyramidal temples of ancient Babylon. Ziggurat is just too big a word, Smith said, explaining that his shorter name seems more intimate, and it doesnt have to be as high as the towers of Babylon; but it is a vertical structure of more than one level. The complex, shifting planes of the Zigs, reminiscent of early Cubism, complements the geometric volumes of the Cubi series in the next room. The play of curved tubular forms in Zig IV 1961, in particular, resembles a Cubist relief, with a tilted platform that suggests the frame of a picture as much as a sculptural support.
Smith painted the Zigs using automobile enamel, ostensibly to protect the steel when they were placed outdoors, and created expressive painterly effects on the sculptures surfaces. For Smith, there was nothing extraordinary about this practice, and he related his own approach to the painted sculptures of the ancient world, and the coloured surfaces of early Cubist constructions.