Though Hans Hartung's unmistakable style had already begun to appear in the 30's, the breakthrough arrived only after the war, when his artwork became famous. At first, Hans Hartung fell between two categories through his stubornness. A long trajectory was in store. He was celebrated as one of the most important representatives of the Paris School at a time when his art was already mature enough to stand on its own and lead him to become the father of Action Painting. He was one of the first Informal artists. Everything can be traced far back to his school days in Leipzig in 1922. His art lay between two fronts: on one side, the Bauhaus and Concrete Art front, and on the other, Sachlichkeit (Objectivity) and Surrealism. Abstract Expressionist art sought a wider field. Gradually, Informal Art was born, and Hartung intensely subscribed to it since the 30's. The Cobra Group from the 50's lent this movement renewed energy and support.

He creates a considerable painterly oeuvre. For Hartung, there was always 'the dark call of colors and the attempt to fuse opposing forces into a whole'. Soon the wide strips of color applied by brush and scraper are the focus of his paintings. India ink becomes the protagonist. In 1922 Hartung created a watered India ink drawing of a church interior. As if Tiepolo had spread his shadow script, this drawing appears absolutely abstract. The cross-hatching of light and the night breaking into the space seeps with the premonition of a later formality. An interplay of light and darkness characterized by an application technique in varying tempos. There are paintings from the 30's that recall Bissier's meditation formulas. Brush and pen, paint or ink, red chalk, chalk and pencil are the graphic media. Scratching surfaces with different scrapers took the upper hand by 1962. The scratch, one of the earliest fruits of human creation, becomes part of his artistic language. Iron sculptures from the 30's reflect the visions appearing in his paintings and which are nearly tangible.