Full time American artist since 1972, McKnight's brilliant use of color in a highly individual, simplistic, style creates images which are acclaimed by professionals and non-professionals alike.    Drawing on personal experiences and visits mainly to Greece and Japan  his landscapes, cityscapes and interiors are much sought after and are now permanently displayed at New York's Metropolitan Museum of Art and the Smithsonian Institute as well as in his own gallery at Litchfield, Connecticut.   Six books, including 2 in Japanese, have been devoted to his work.