Mondrian produced Lozenge Composition With Four Yellow Lines (1933), a simple painting that innovated thick, colored lines instead of black ones. After that one painting, this practice remained dormant in Mondrian's work until he arrived in Manhattan, at which time he began to embrace it with abandon. In some examples of this new direction, such as Composition (1938) / Place de la Concorde (1943), he appears to have taken unfinished black-line paintings from Paris and completed them in New York by adding short perpendicular lines of different colors, running between the longer black lines, or from a black line to the edge of the canvas. The newly colored areas are thick, almost bridging the gap between lines and forms, and it is startling to see color in a Mondrian painting that is unbounded by black. Other works mix long lines of red amidst the familiar black lines, creating a new sense of depth by the addition of a colored layer on top of the black one. His painting Composition No. 10 , 1939–1942, characterized by primary colors, white ground and black grid lines clearly defined Mondrian's radical but classical approach to the rectangle.