Born in Krommenie in 1905, Klaas Boonstra started out as an independent painter working in an experimental abstract style. In 1940 he settled in Amsterdam and was swept up in the city's turbulent post-war artistic scene. He painted abstract compositions featuring a dynamic interplay of colourful, random shapes that evolved as an intuitive part of his working process. The influence of Picasso and Matisse is particularly evident in his pictures from the 1940s. In 1951 Boonstra joined with Willy Boers, Brands, Rooskens and several others to form Creatie, and Boonstra later became a member of Groep 54 and Liga Nieuw Beelden.