Only now [1943] I become conscious that my work in black, white and little color planes has been merely 'drawing' in oil color. In drawing, the lines are the principal means of expressions... In painting, however, the lines are absorbed by the color planes; but the limitations of the planes show themselves as lines and conserve their great value.
a postcard note, late May 1943; as quoted in Mondrian, - The Art of Destruction, Carel Blotkamp, Reaktion Books LTD. London 2001, p. 240