Judd based his work on simple mathematical formulae, in order to avoid subjective, 'expressive' qualities. 'Reading' this sculpture from left to right, the steel blocks decrease by just under half their size, while the spaces between them do the same, but in reverse. The smallest space and the smallest solid have the same dimensions. Judd deliberately made his art to look as if it had been made by machine. Much of his work, including this one, was fabricated by the firm of Bernstein Bros., on Long Island. The contrast in the colours of the materials is a key element.