An art style popularized in the 20th century, it refers to artwork whose subjects are shapes based on simple geometry such as straight lines, circles, squares and rectangles. In contrast to Abstract Expressionist painting, Geometric Abstract shape colors are distinct, not blended, and often are delineated by bold colors. Pioneering Geometric Abstract painters were the Russian, Kasimir Malelvich (1878-1935), and Dutchman, Piet Mondrian (1872-1944). American sculptors and painters include include Carl Andre, Frank Stella, Patrick Henry Bruce, and Allan d'Arcangelo. Sources: Ralph Mayer, "A Dictionary of Art Terms and Techniques"; AskART biographies.