Judd wanted to remove all physical traces of the artist's hand from the making of a work, believing that they would distract viewers. From the mid-1960s, all his works were fabricated industrially according to his specifications. The seductively uniform surface of this work, enhanced by the reflective finish of the copper, calls attention to its industrial origins. The four projecting sections follow a simple arithmetical progression, their widths increasing by 1.5 inches from left to right. The spaces in between are determined by the same progression, but in reverse order.