[1][2] After he established his own ceramics workshop in Oslo in 1933, he joined the company with Andreas Thiele Schneider in 1937.
That same year, William Knutzen participated in the Norwegian Pavilion at the World Exhibition in Paris.
From around 1940 he often worked with chamotte ceramics with coarse, elegantly sharpened patterns and bold colors on creamy tin glass.
At the same time as he established a new workshop in 1949, he also became an artistic director of Arnold Wiig's Fabrikker in Halden.
Knutzens works from the early 1950s are characterized by an experimental abstract form in partially glazed red-colored.