Sonia, Robert and their son Charles returned to Paris permanently in 1921 and moved into Boulevard Malesherbes 19.
The Delaunay's most acute financial problems were solved when they sold 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.
