Sol LeWitt’s early wall drawings, which feature lines going in the four basic directions, embody his interest in systematically exhausting all possible combinations of different elements. This process can be seen in Wall Drawing 47 (located nearby at MASS MoCA), in which the artist depicts all fifteen possible combinations of the four basic types of lines. These combinations are drawn in graphite in fifteen vertical panels that divide the wall. Wall Drawing 85 reiterates this process using colored pencil.
The artist’s understanding of the superimposition of color came from his knowledge of printmaking and commercial printing. The red, yellow, blue, and black pencil that he uses to draw the four basic types of lines mimic the ink colors that commercial printers use. By layering these four basic colors, as is done in printing, LeWitt produces secondary colors.