For instance in the 1940s Ambellan and his fiancée Elisabeth Higgins hosted both Pete Seeger and Woody Guthrie at 31 East 21st Street.
After the collapse of Federal Arts Project grants and building on the achievements of the WPA's New York Poster studio, Ambellan explored silkscreening as a method of decorating ceramic tiles.
[6] With the help of a manager and despite the war, travel and their late 1940s divorce, the Ambellans operated Designed Tiles from 1941 to 1958, when it was sold to friends, the Sklanskys.
Although the artists who became known as the Abstract Expressionists were among his friends in New York, Ambellan remained committed to the figurative in both his sculpture and painting.
After living several years in Montparnasse, one of the principal artistic communities of Paris, Ambellan decided to settle in the Greek-Roman enclave town of Antibes on the Côte d'Azur.