Heijo Hangen (born 1927) gained international attention in 1977 as a participant in documenta 6 and is considered one of the most significant representatives of systematic-concrete art in Germany. The painter developed his unique image system of double diagonal division of a square and consistently explores its design possibilities. His focus is not only on the individual painting but also on working in series and variations. In his "time-shifted image combinations," for example, he reassembles works from different creative phases into harmonious overall ensembles. Thus, the artist achieves a highly vibrant and distinctive sequence of images with varying proportions and rich colors, despite a strict concept.