In various places, particularly in the USA, Ernst Keller is referred to as the father of Swiss Style, later known as International Typographic Style, when writing the history of graphic design. This recognition is due to the large number of Keller's students who later shaped and popularized this Swiss Style. Keller's achievements are evident through his oeuvre, primarily his poster designs and his work on lettering and graphic design in architecture. His contribution to the development of innovative, non-academic didactic principles in design training is fundamental. His teaching activity, which began in 1918, can be defined as one of the first systematic training programs for graphic design in the world. His many years of teaching between 1918 and 1956 resulted in a diverse range of designers, including key figures in new graphic design such as Richard Paul Lohse, Josef Müller-Brockmann, and Carlo Vivarelli, as well as talents in artistic illustration like Heiri Steiner, Lora Lamm, and K. Domenic Geissbühler, and innovative designers such as Hermann Eidenbenz and Gérard Miedinger. Additionally, there were scientific illustrators like H.P. Weber and caricaturist H.U. Steger. Another group consists of designers who teach internationally, including Pierre Gauchat, Walter Käch, Robert Sessler, Fred Troller, and Josef Müller-Brockmann. This diversity of talent is an impressive testament to the openness, sustainability, and rejection of dogma evident in Ernst Keller's teaching.