To watch a Zen painter is to receive a lesson in the discipline of Zen. As he sets out to create a work, he first brings to hand the essential artistic materials: brush, inkstone, ink, paper. Kneeling on the floor, he spreads the paper out before him, and as he grinds and mixes the ink, begins to envision the outline and scope of his work. Like a _samurai_ warrior before a battle, he banishes thoughts of the world and in a state of contemplation organizes his energies for a burst of action. When the ink is ready, the paper smoothed, an appropriate brush tested for point and feel, and his spirits composed, he strikes. The ink is absorbed almost immediately by the fibrous rice paper preferred by Zen artists, allowing no alteration of a line once it has been set down. If the artist is dissatisfied with a stroke, he attempts no corrections but tears up the work and begins another. In contrast to conventional Western oil painting, which allows for retouching, an ink brushstroke on paper (or silk, which is sometimes used) becomes dull and lifeless if it is painted over, and corrections are always obvious when the painting dries. The work must flow out of the Zen discipline of no-mind. The artist never pauses to evaluate his work; the ink flows in an unending flurry of strokes--heavy or sparing, light or dark, as required--producing a sense of rhythm, movement, form, and the artist's vision of life's inner music. The discipline of ink painting was only one of the qualities that endeared it to Zen painters. Equally important was the understated, suggestive art it made possible. Learning from the Chinese, Ashikaga Japanese discovered that black ink, carefully applied to suggest all the tones of light and shade, could be more expressive and profound than a rainbow of colors. (A similar lesson has been learned by modern photographers, who often find black and white a medium more penerating than color.) The Chinese painters of the T'ang and Sung dynasties were the first to discover that black ink could be made to abstract all pigments and thereby suggest, more believably than actual color paintings, the real tones found in nature. Whereas the medium of ink has been used in the West primarily for line drawings and lithographs, the Eastern artists use ink to produce the illusion of color--an illusion so perfect that viewers must at times remind themselves that a scene is not in full polychrome. And just as the seemingly unfinished artistic statement nudges the viewer into participating in a work, the suggestive medium of monochrome with its implied rather than explicit hues tricks the viewer into unwittingly supplying his own colors. The Zen insight that the palette of the mind is richer than that of the brush has been best described by a Japanese artist and critic, who explained the rich suggestiveness of black ink, called _sumi_ by the Japanese: