With his participation in documenta 6 in 1977, Heijo Hangen (b. 1927) attracted international attention and is now considered one of the most important protagonists of systematic Concrete Art in Germany. He developed his own pictorial system based on the double diagonal division of a square and, since then, has continuously rearranged works from various phases. He thus creates an extremely lively and unmistakable sequence of images of various proportions and rich colouration. ukryj opis