Mainly self-taught, Bortnyik worked as a graphic designer at the Savoy Company. In 1917, he met Kassák and became a member of the avant-garde newspaper MA (Today), first in Hungary and later in Vienna. He developed his own style, called Picture Architecture, considered the Hungarian answer to Constructivism. In 1925, he moved to Weimar, where he was influenced by the Bauhaus and founded his own advertising studio. Back in Budapest, he managed the avant-garde Green Donkey Theatre and founded the Műhely art school, while continuing to undertake commercial work. After the Second World War, he turned to political posters, becoming editor of Free Art magazine and director of the University of Fine Arts.