Composition No. 12 with Blue holds a particular place in Mondrian's work. The artist began it in Paris in 1936, and finished it in 1942, when he was living in New York. Mondrian inscribed the two dates on the black line to the right of the blue square, contrary to his usual habit of assigning to a painting the date of its first public showing.
In this work, Mondrian expresses the Theosophical opposition of spirit versus matter through the contrast of vertical elements (the principle of the will) and horizontal elements (the principle of rest), and through the opposition of black-and-white and primary colours.