Bühler studied in 1925–27 at the Allgemeine Gewerbeschule in Basel, and in the following two years (with O.H.W. Hadank) at the Vereinigten Staatsschulen in Berlin. Then he went to Paris, before working in a Basel agency. In 1933 he opened his own studio in Basel, working with important designers such as Barth and Piatti. He saw advertising as a tool to convert the general public to art. He also gave evening classes at the Gewerbeschule, specializing in graphic design and posters. Bühler had a great range of activities: he designed posters, periodicals, exhibitions, promotional films and packaging, and excelled in all these areas. His poster for Union Coal became a huge success. Bühler was for many years an advisor on matters of design for several large companies. He was the fourth president of AGI and devoted much of his energy and love to the organization. He also designed the catalogue for the Lausanne AGI Exhibition 1957; the cover image was used as a giant mural.