Ernst Keller was born 1891 in Aarau, Switzerland. Keller was first trained as a draughtsman and lithographer in 1906. He worked in Leipzig, Germany until 1914. Keller joined Zurich's famous Kunstgewerbeschule (School of Applied Art) in 1918 until he retired in 1956. As a teacher he was the most important single influence on the development of the Swiss style while teaching design and typography. Where he then established several training programs in design and typography and was called "the father of Swiss graphics". The economically drawn images and inventive lettering of his posters designed in the 1920s and 30s made an important contribution to Modernism.
Keller created a design system characterized by a rigid grid format, structured layout and unjustified type. The core of these ideas were first presented in the book Grid Systems in Graphic Design by his student Josef Muller-Brockmann.
Willy Rotzler writes of him in Graphis 184 in 1976 that "He was instilled with the belief that every piece of graphic design ought, over and above the its immediate purpose, to be an improvement of our visual environment. It the final analysis it was this fundamental ethical principle that lent lasting value to the work of his pupils, making Swiss graphics not merely the name of a style, but a seal of quality."
Keller is famous for his posters for the Kunstgewerbemuseum Zurich, for several charity organizations, for heraldic logos (like the one for the canton of Glarus) and after his retirement for his work as a sculpture. He died 1968 in Zurich/Switzerland.