After an apprenticeship as an ivory-carver, sculpture studies and military service, Lortz started a voluntary job at a printer in Reutlingen in 1946. In 1948 he was commissioned to design book covers for Rowolt, Desch, Insel and DVA. In 1949 he worked at the graphic department of the US Headquarters in Frankfurt; he also designed a building exhibition in Nuremberg. He became the first German AGI member. Lortz taught at Darmstadt Art School (1952–59) and received the Art Award of Darmstadt (1956). In 1957 he became a founder member of the graphic group Novum. In 1959 he became a professor at Berlin Hochschule für Bildende Kunste; he designed its logo in 1975. Lortz designed the German section at Italia 61, Turin. Darmstadt honoured Lortz with the Johann Heinrich Merck Award, 1970. Between 1972 and 2004 fourteen books were published on Lortz as an illustrator, draughtsman, photographer, teacher, friend, photomontage artist, portraitist, sketcher and human being.