Sol LeWitt began making his iconic open-grid geometric structures in the mid-1960s. At the same time, he formulated a serial approach to art making in which the progression or development of a structure was preset by an initial determining idea. He used the cube as his basic primary structure and the common denominator of works which followed the mathematical principle of elementary progression through addition or subtraction. Initially painted black, by the late 60s his open-grid structures were universally painted white. They were constructed either from wood or of enamel on aluminum. Others were made of steel. Although the progressions or permutations of LeWitt’s modular forms appear logical, he has emphasized the intuitive nature of his process.

To work with a plan that is pre-set is one way of avoiding subjectivity. It also obviates the necessity for designing each work in turn. The plan would design the work. The objects are made by assistants according to LeWitt’s instructions. By minimizing his physical presence in the process of fabrication, LeWitt emphasizes the impersonality of these structures.

LeWitt's structures strip his conceptual work down to its bones. The skeletal cubes acted as a base of which he would then build on or elaborate with other minimalist techniques. LeWitt's structures followed the agenda of removing the 'skin' from art, an idea popular in the '60s.