After the war, Ludwig attended the Stuttgart Academy where he was introduced to colour theory and print-making. In 1919 he enrolled at the Weimar Bauhaus where he studied under the star teachers: Johannes Itten, Paul Klee, Wassily Kandinsky. Hirschfeld-Mack's main activities at Bauhaus focused on the problems of colours and colour projections. With his didactic toys, for example, he demonstrated how the rotation of the top produces the optical mixing of the colours that were printed upon the laid-on plates.
Hirschfeld-Mack was apprenticed to Lyonel Feininger in the print workshop, completing his training in 1922 and concentrating on the application of colour theories. It resulted in his best-known achievements at Bauhaus, colour-light plays. Hoping to capture the actual movement implied in the illusionary tensions of abstract art, he built and operated an apparatus that combined moving projections of coloured light, mechanical templates and music of his own composition. Young Ludwig must have been an impressive musician in his own right.
He published a booklet, Farben Licht-Spiele, Wiesen-Ziele-Kritiken 1923 and gave travelling performances
Beautiful Bauhaus toys can be found in Jenny Tondera's blog
In one of those appalling ironies of war, Hirschfeld-Mack was deported to Australia as an Enemy Alien in the SS Dunera in 1940. He was interned in 3 prisoners’ camps (Hay, Orange and Tatura). There he made a number of woodcuts that illustrated life for the prisoners.
Released in 1942 through the sponsorship of Geelong Grammar’s head master, Hirschfeld-Mack was appointed the school’s art master. He promoted his pupils' self-knowledge, introduced them to avant-garde painting techniques, and encouraged wood-carving, instrument-making, weaving and leatherwork. He retained the Bauhaus principles of self-knowledge, economy of material, and reform of society through art.