In 1969, his art reaches a turning point when he discovers photography as a model and produces his first large-format picture. From then on, he creates works which, starting from photographs or slide projections, come close to photorealistic art, yet follow their own logic. In the 70s, he produces situation portraits of families and groups of people.The artist experiences his international breakthrough with his participation in documenta V in 1972. In 1978 and 1999, he takes part in the Venice Biennale, and in 1980 begins his portrait series of Irene, Tabea, Verena, Christina, and Johanna.

In 1986, he temporarily abandons painting for eight years to devote himself to large-format woodcuts, which he gives a special status. When he resumes painting, he makes a series of grasses and again portraits. His works are exhibited internationally in museums like Les Abattoirs in Toulouse. Until today, the artist continues to work on existing and new series.

Franz Gertsch occupies an important position in Swiss art. A museum dedicated to him opened in 2002, and the Swiss Post issues special stamps featuring his woodcut motifs in 2012. In the course of his career, Gertsch has received several scholarships, such as the DAAD scholarship, as well as prizes and honours, among them the award of honorary citizenship of the Christian-Albrechts-Universität zu Kiel and the Kaiserring of the city of Goslar.