Thon is largely self-taught, one month's work at the Art Students League, New York, constituting his only submission to formal training. He was an office worker, a bricklayer's helper, and assistant billboard painter, while developing his skills by consistent, independent, drawing and painting. His life-long habit of travel began in 1933 when he made an eight-month voyage to Cocos Island in the Pacific.
His debut as a professional artist was in the Corcoran Gallery of Art, Washington, D. C., biennial exhibtion of 1939; in 1942 his work was included in the Artists for Victory show mounted by the Metropolitan Museum of Art, New York. Two years later the Midtown Galleries presented Thon's first one-man show; Midtown continues to represent him.
After seeing active service in the Navy during World War II, Thon, at the suggestion of Stow Wegenroth, settled in Port Clyde, Maine. He almost immediately went to Italy, having been awarded in 1947 a Prix-de-Rome fellowship to the American Academy in Rome. Thon had worked in the oil media up to this time, and continues to do so, but it was during this first stay in Italy that he worked in watercolors. Since that time the artist has practiced both media in nearly equal measure; it was in the watercolorist classification that Thon was elected to membership in the Academy.
Thon has frequently returned to Italy--in 1955, by invitation of the American Academy to serve as artist-in-residence--and traveled elsewhere in Europe. Along with the constant themes of his Maine and Italian environments, scenes from Spain, Portugal, Ireland, and Greece supply the basis of his highly abstracted landscape paintings, which, as a New York Times reviewer noted in 1952, are "characterized by paint texture of enourmous refinement. Patterns like frost crystals, spidery lines and stains of color seem breathed onto the picture rather than painted."
Thon has consistently exhibited paintings in both oil and watercolor media in Academy annual exhibition, and has been honored with the Palmer Prize in 1944; Anonymous Prize in 1949; Altman prizes in 1951, 1954, 1961, 1967 and 1969; the NAD Prize in 1955; Morse Medal in 1956; Obrig Prize in 1965; William A. Paton Prize in 1980; and Ogden Pleissner Memorial Prize in 1988.
Bates College, Lewiston, Maine, conferred an honorary doctorate of fine arts degree upon Thon in 1957.
