The 1940s and 1950s saw abstraction become the dominant aesthetic in painting and sculpture in Europe and the United States. Abstraction covered many different styles, and was known by many different names.
Abstract Expressionism was the generic term for the American painters, based mainly in New York. The name evokes their aim to make art that while abstract was also expressive or emotional. Inspired by the Surrealist idea that art should come from the unconscious mind, abstract expressionism fell into two groups: the ‘action painters’ led by Pollock and De Kooning, and the colour-field painters, notably Rothko, Newman and Still. The action painters worked in a spontaneous manner, often using large brushes to make sweeping gestural marks. Pollock famously placed his canvas on the ground and danced around it pouring paint direct from the can or trailing it from the brush or a stick. The colour field painters were deeply interested in religion and myth. They created simple compositions with large areas of a single colour intended to produce a contemplative or meditational response in the viewer.
In Europe, the French term Art Informel became the generic label to describe the many styles of improvisatory non-geometric abstract art that proliferated in the 1940s and 1950s. As in the US, there was a great variety of styles: Hartung developed a vigorously gestural painting that was the expression of spontaneous feeling, and the result of direct physical action, much in the same way that the holes in Fontana’s works can be seen as the most literal marking of the movement of the artist’s hand. However, the puncturing of the surface of the work was also an attempt to introduce the notion of the infinite as a dimension beyond the surface, an aim keenly shared by Klein, whose monochrome paintings he associated with immaterial values beyond what can be seen or touched.