designs. Poiret declined, claiming she had copied designs from his Ateliers de Martine and was married to a French deserter (Robert). Galerie der Sturm in Berlin showed works by Sonia and Robert from their Portuguese period the same year. Return to Paris (1921–1944) Sonia, Robert and their son Charles returned to Paris permanently in 1921 and moved into Boulevard Malesherbes 19. The Delaunays' most acute financial problems were solved when they sold Henri Rousseau's La Charmeuse de serpents (The Snake Charmer) to Jacques Doucet. Sonia Delaunay made clothes for private clients and friends, and in 1923 created fifty fabric designs using geometrical shapes and bold colours, commissioned by a manufacturer from Lyon. Soon after, she started her own business and simultané became her registered trademark. For the 1923 staging of Tristan Tzara's play Le Cœur à Gaz she designed the set and costumes. In 1924 she opened a fashion studio together with Jacques Heim. Her customers included Nancy Cunard, Gloria Swanson, Lucienne Bogaert and Gabrielle Dorziat. With Heim she had a pavilion at the 1925 Exposition Internationale des Arts Décoratifs et Industriels Modernes, called boutique simultané. Sonia Delaunay gave a lecture at the Sorbonne on the influence of painting on fashion. Sonia designed costumes for two films: Le Vertige directed by Marcel L'Herbier and Le p'tit Parigot, directed by René Le Somptier, and designed some furniture for the set of the 1929 film Parce que je t'aime (Because I love you). During this period, she also designed haute couture textiles for Robert Perrier, while participating actively in his artistic salon, R-26. The Great Depression caused a decline in business. After closing her business, Sonia Delaunay returned to painting, but she still designed for Jacques Heim, Metz & Co, Perrier and private clients. She said "the depression liberated her from business". 1935 the Delaunays moved to rue Saint-Simon 16. By the end of 1934 Sonia was working on designs for the 1937 Exposition Internationale des Arts et Techniques dans la Vie Moderne, for which she and Robert worked together on decorating two pavilions: the Pavillon des Chemins de Fer and the Palais de l'Air. Sonia however did not want to be part of the contract for the commission, but chose to help Robert if she wanted. She said "I am free and mean to remain so." The murals and painted panels for the exhibition were executed by fifty artists including Albert