Using the grid as his basic ingredient, Sol Lewitt revolutionized the definition of art in the 1960s. Starting from the simple but radical idea that an artwork's concept is more important than its form, LeWitt conceived Conceptual Art, rejecting the dominant, emotionally charged abstract style of artmaking and favoring impersonal, geometric forms. Lewitt applied his theories to a multitude of media; painting, sculpting, drafting, printmaking and wall drawings.
Lewitt’s first important drawings were also derived from the grid. As in Four Color Drawing from 1971, their basic configuration is parallel lines and their direction the cardinal points and the intermediate points, or vertical, horizontal and the two diagonals. Lewitt also considered the primary characteristics of a line- straight, not straight, and broken- producing a large group of drawings with his ingenious variations based on these rubrics. The artist refined this pattern, first by developing extraordinary skill and control in maintaining an even, narrow space between the lines, and through his precise method of color use. By repeating and varying a single principle, he created sculptural structures on paper. Beyond his use of basic shapes like squares, circles, rectangles and cubes in drawings, LeWitt also experimented with isometric forms and volumes, pyramids and trapezoids in ways that were simultaneously rigorous and playful. Rendered in a variety of colors, these deceptively simple drawings display an extraordinary variety.
Over the years, LeWitt's austere compositions gradually became more complex and sensuous, though they remained true to his original precepts. This late period saw LeWitt depart from rigid geometry in favor of free-flowing lines in a vibrant palette of primary colors alongside black and white, as in Vertical Brushstrokes, 1994 and Horizontal Brushstrokes, 1995. These works signaled a significant shift from his previous practice, with regard to his chosen medium and the visible presence of the artist’s hand. LeWitt’s gouaches are integral to his overall oeuvre, focusing on the primacy of the line and the fundamentals of art making.
Lewitt continued to challenge new thinking about what art can be. "If the artist carried through his idea and makes it into visible form, then all the steps in the process are of importance. The idea itself, even if not made visual, is as much a work of art as any finished product," stated LeWitt in 1971. "All intervening steps, scribbles, sketches, drawings, failed work models, studies thoughts, conversations, are of interest. Those that show the thought process of the artist are sometimes more interesting than the final product." (LeWitt, 'Paragraphs on Conceptual Art', Artforum Vol.5, no. 10, Summer 1967, pp. 79-83)