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 large floods of color, Louis let unprimed canvas dominate his paintings. As is exemplified by the Modern’s Beta Mu, he began to use thin vertical and diagonal lines in smaller areas, typically along the edges. The largest portion of the canvas, the V-shaped center, is completely bare. Louis’s late style exemplifies his evolution from solid color to spacious canvases with sparse color, although his artistic focus always remained on investigations of pure color and space.