Judd had occasionally used diagonal dividers within his works since the early 1960s, but it was not until the late 1970s that he began to explore their potential in a comprehensive manner. This simple device enabled him to dynamically modulate space within an open-fronted unit, initially in plywood and later in metal. Untitled (1982) consists of three units, each divided in a different way. The aluminium frame is backed by purple Plexiglas, creating subtle light and colour effects within each unit.
These ideas were developed further in Untitled 1986, an ambitious wall-piece. Each plywood box is identically-sized with a coloured Plexiglas rear-wall that is revealed or concealed by the dividers. The patterns vary, depending on the position of the viewer, so that walking across the front of the work reveals an ever-changing panorama of colours. Each unit is different. Judd had calculated all the possible variations that could be created by combining dividers, before selecting 63 for fabrication, of which 30 were eventually completed.