Well known since 1960s for his sculptures, graphics, and wall drawings, Sol LeWitt has been a major force in the artistic movement known as Conceptualism. Concepts or ideas are the basic materials of LeWitt’s art, which often exist as a set of detailed instructions. In “Conceptual Art,” he explains, “the idea or concept is the most important aspect of the work. When an artist uses a conceptual form of art, it means that all of the planning and decisions are made beforehand and the execution is a perfunctory affair.” After the artist develops a concept, a team of artisans fabricate the artwork by following a specified plan. In X with Columns, as in a number of his other works, LeWitt uses geometric forms and neutral materials--cinder blocks and concrete. The artist says that he was attracted to this unlikely medium “because it was a totally ‘non-art’ one” with no historical associations. The low-tech masonry process lends itself to the basic geometric shapes he favors.