Trump was a professor from 1927-1930 at the Trades and Crafts School in Bielefeld and, with Paul Renner and Jan Tschichold, taught type design and typography. For the following four years he served as director of the Higher Graphic School in Berlin and designed fonts for H. Berthold AG. From 1934–53, Trump succeeded Paul Renner as director of the Meisterschule für Deutschlands Buchdrucker in Munich. After 1953, Trump freelanced, receiving increasing international recognition. He designed 17 typefaces, including City (1930), Delphin I (1951), Time Script (1956), Trump Mediaeval (1960), Jaguar (1964), and Mauritius (1967).