'Two Open Modular Cubes/Half Off' is one of a very large number of works by LeWitt using open cubes in various simple sequences or combinations. It belongs to a group (totalling fifteen at the time this work was bought by the Tate Gallery) of works on this particular large scale to which the basic single cube is progressively added to in various permutations, the works becoming more complex while always retaining their clarity of identity as a combination of identical open cubes. This characteristic simple complexity is most marked in the half-off pieces, in which the cubes are joined halfway along their sides instead of being aligned. Another half-off work in this group has three cubes, and another five, alternatively projecting and receding in a zigzag formation. Five was the maximum number of cubes the artist deemed appropriate for this scale. LeWitt has said that he did not attempt to explore all the possible permutations of the five cubes but chose those which were 'the most poignant (simple, basic, intelligible)'. He decided that the scale of these works should be human and the height of the cube, 1600mm, is approximately the artist's eye level. Most of them were manufactured in Holland from aluminium square section tubing. The metal is stove enamelled but LeWitt has said that any white, not-too-glossy semi-permanent surface would do.
Simon Wilson, Tate Gallery: An Illustrated Companion, Tate Gallery, London, revised edition 1991, p.263