Walter Dexel, a Munich native, studied art history under Heinrich Wölfflin and Botho Graef. Beginning in 1916 he concentrated on painting in addition to commercial art; the influences of Paul Cézanne, Cubism and Expressionism are clearly evident. In the early 1920s, Dexel turned to figurative and later abstract Constructivism. All his life he also worked as a designer of illuminated and outdoor advertising. The first lighted street sign from 1925 is considered his invention. Beginning in 1926, Dexel was a collaborator in the 'New Frankfurt' under Ernst May, and was greatly involved in the social reform movement of the same name.