From 1964 to 1971, he studied under Joseph Beuys at the Kunstakademie Düsseldorf[2] with fellow students Blinky Palermo (with whom he shared a studio and a love), Jörg Immendorff, Ivo Ringe and Katharina Sieverding.
[9] This later evolved to his placing slides covered in copy ink with precisely carved vertical and horizontal lines into the projector and then cast throughout the room.
Projecting these lines at various angles throughout a darkened space, at windows, corners, wall fittings and architectural irregularities, offered limitless possibilities for the artist.
Knoebel's 1968 Projektion 1, is a series of luminous, disorienting black-and-white photographs of light projections that bring to mind the architectural slicings that Gordon Matta-Clark was conducting at that time.
During a nocturnal drive through the sleeping city of Darmstadt, a large, luminous X-shaped beam of light was projected from a vehicle onto the walls of buildings.
[13] His painting has since been characterized by a gesturally expressive application of colour on panels of layered plywood and metal placed in specific spatial relation.
More than a century after being severely damaged by German bombing raids, Knoebel designed three new stained glass windows for the Reims Cathedral.
In 1996 the Haus der Kunst, Munich, staged a large retrospective of his works which travelled throughout Europe, including such venues as the Stedelijk Museum, Amsterdam, and Institut Valencià d'Art Modern, Centre Julio González, Valencia.
Knoebel had a major retrospective in summer 2009 at the Hamburger Bahnhof and the Neue Nationalgalerie in Berlin;[17] the Neue Nationalgalerie showed an arrangement of monumental key works relating to the upper hall of the famous Mies van der Rohe building, as well as gestural painting in various shades of white, which used the glass panes surrounding the upper storey of the building.