(Dutch: “Style”). De Stijl was a movement founded in 1917 in Leiden, Holland, by painter Piet Mondrian, architect/painter/writer Theo van Doesburg, and painter/interior designer/graphic designer Bart van der Leck. Proponents of De Stijl advocated a universal visual language of pure abstraction, known as Neo-Plasticism, which could be achieved by simplifying compositions to vertical and horizontal lines and using only black, white and the primary colors. Pronunciation here. Web resource here.