Rejecting traditional modes of composition based on aesthetic judgement, Judd sought new ways of giving structure to his work. By inserting the ends of an angled metal pipe into the centre of two wooden panels, Judd used this found object to determine the size and form of Untitled 1962, one of his first free-standing works.
The move into three dimensions offered Judd new possibilities. Whether an object was mounted on the wall or placed directly on the floor, he became fascinated with defining both inner and outer space. In Untitled 1963, the assemblage of bars joining two vertical planes defines the space without enclosing it. Judd believed that allowing this interior view gave the work a greater honesty than traditional sculpture, which excludes the possibility of a view into the space it occupies.
From 1961 Judd increasingly used light cadmium red oil to colour his paintings and objects. Judd favoured this colour because he felt that it showed up the edges, lines and textures of the work, unlike black, for instance, which tended to obscure them. In Untitled 1963 he combined this colour with purple Plexiglas, a material that he was to use frequently because of its inherent — and thus more honest — colour.