Known primarily for his wall drawings as well as his many variations of open cube structures, Sol LeWitt created important works on paper throughout his career. Beginning in the 1980s, the artist expanded the visual vocabulary of his practice—which had been defined by basic geometric forms and sets of rules—to include multifaceted shapes, increased spatial depth, isometric projection, and tonally complex colors. By the 1990s LeWitt moved to even more open-ended methods of composition, employing gouache, an opaque water-based paint, to produce free-flowing abstract works in contrasting hues. In 1992, his drawings were the subject of a major traveling exhibition organized by the Haags Gemeentemuseum in The Hague, Netherlands.