Composition with yellow lines

In 1933 the painter Charley Toorop got a circle of Dutch artists and architects to put money together so that a museum at home would own a Mondrian, and what reached The Hague was this diamond. There is no black in it. For years he had held that the lines in a painting must be black and that colour belonged in the rectangles between them, and here four yellow bands cross the white ground, none of them touching another. The museum's own description calls them too thin to be planes and too thick to be simply lines. Mondrian, in Paris, worried the canvas would be hung as a square and wrote instructions on the back explaining how to turn it. When the museum's new building opened in 1935 the picture went up in a stairwell.