Morris Louis is best known for his "stain" paintings, which he made by pouring a mixture of paint and turpentine directly onto unsized and unstretched canvases that he would then tilt and manipulate to create abstract shapes and fields of color. From 1954 to 1959 he used the stain method to create his Veil series, which marked the beginning of his mature style. By 1960 Louis’s Veil series was complete, and his style began to change. He still poured paint onto canvases that were loosely tacked to their stretchers, which he maneuvered to make his colors run; but instead of...