Around 1913, he and Otto Gutfreund, produced some of the earliest Cubist sculpture made anywhere. Before World War I he moved to Paris, but left for the Netherlands when war broke out. He returned to Prague after the war. During the 1920s, he further developed his version of Synthetic Cubism and rejoined Mánes. Like many Czech modernists, he was active in design as well as in painting; in 1925 he designed paintings on glass for the Czechoslovak Pavilion at the International Exposition of Modern Industrial and Decorative Arts in Paris. In the late 1920s and early 1930s, Surrealist influence also began to show in his painting and sculpture, and he was a participant in Poesie 1932, an international exhibition in Prague that introduced Surrealism to the Czech public. He did not, however, become a Surrealist.