(b Voiron, Isère, 4 Aug 1885; d 1958). French painter and illustrator. From 1887 to 1898 Mainssieux was confined to bed due to illness and it was then that his first interest in drawing developed. He was taught by Jules Flandrin, whose dogmatic, analytical approach to painting suppressed Mainssieux’s spontaneity and enjoyment. From 1902 to 1910 he produced little work, concerning himself mainly with technical problems. In 1905 he moved to Paris, studying under Jean-Paul Laurens and meeting André Dunoyer de Segonzac, Jean-Louis Boussingault and Luc-Albert Moreau, whose artistic tastes he shared. Two years later he first exhibited some landscapes and portraits at the Salon des Indépendants, the former influenced by Ando Hiroshige as well as by Flandrin.