"The goal should be an understanding by all three parties: the wall, the architect and the painter", observed the French artist Fernand Leger (1881-1955) in 1933. His projects reveal a willingness to try out new things and demonstrate his striving to extend painting beyond the boundaries of the easel and to integrate it into the social, everyday space. They shed new light on one of the influential artists of the twentieth century. Fernand Leger, known for his Cubist paintings and his representational works of the mechanical period, was a trained architectural draughtsman who from the early 1920s until the end of his life made an intensive study of the interrelationships between painting and space. He was convinced that the social and psychological dimension in the use of colour contributed to a better integration of modern architecture into everyday life and human existence. In close dialogue with architects like Wallace K. Harrison and Le Corbusier he produced fascinating, often unexpectedly experimental and frequently abstract projects for houses, flats, churches, ships and world exhibitions.