Ralf Winkler (Dresden, Germany, 1939 - Zurich, Switzerland, 2017), was a sought-after representative of German neo-expressionism. The painter moved to the RFA in 1980 and since then his work, which includes paintings, sculptures and objects, has been present at the Venice Biennale, the Documenta in Kassel and the most relevant museums and galleries in the world. The artist A.R. Penck combines simplifying abstraction and analytical thinking in his works and, in an attempt to reflect the intricate structures of today's world, creates highly complex social and psychological frameworks.

In his unmistakable pictorial language of signs and figures, expressionism is mixed with primitive art. Ralf Winkler adopted his pseudonym A.R. Penck in homage to a geologist who studied the glacial period.