Georg Karl Pfahler is regarded main representative and key figure of geometrical-abstract "Signalkunst" [Signal Art].
After beginnings dominated by informal art, he made the "formative" images as of 1959 and, as of the 1960s, famous works in the style of "Signalkunst", which show obvious similarities with the "Hard Edge". Characteristic of these works by Georg Karl Pfahler are the lucent striking colors as well as the geometrically reduced, precise contours, often with rounded corners, which suggest interactions in their subtle interplay. Besides paintings and graphic art, Georg Karl Pfahler employed these principles in three-dimensional works, for instance, he showed 'Color Environments' on the 1970 Biennale and designed public spaces such as the VIP lounge in the Munich Olympic Stadium and a conference room in the Reichstag.
Participation in numerous international exhibitions are proof of the importance of the "Signal" artist Georg Karl Pfahler for the history of post-war art.