Stijl, de [Du.,=the style], Dutch nonfigurative art movement, also called neoplasticism. In 1917 a group of artists, architects, and poets was organized under the name de Stijl, and a journal of the same name was initiated. The leaders of the movement were the artists Theo van Doesburg and Piet Mondrian. They advocated a purification of art, eliminating subject matter in favor of vertical and horizontal elements, and the use of primary colors and noncolors. Their austerity of expression influenced architects, principally J. J. P. Oud and Gerrit Rietveld. The movement lasted until 1931; in architecture a few de Stijl principles are still applied.