If up to the mid-1970s Knoebel, inspired by the ideas of Constructivism and Suprematism, had worked mainly with black and white contrasts, in his first experiments with colour he added Menninge paint to his palette for the so-called ‘Menninge’ paintings. The use of Menninge, a red lead paint, was an idea of Palermo’s: ‘Access to colour took place through Mennige paint, an anti-rust paint that covered everything. Palermo worked with it. I once asked if I could use it. Later I tried out Titan, ferric oxide, etc.’
In 1980, in contrast, the ‘Genter Raum’ documented his first-time effort to master the whole colour spectrum. His study of modular forms and colours and their relations to each other came about in a systematic and experimental way ever since his exhibition 24 Farben für Blinky Palermo, in 1977. Knoebel painted each of the irregular objects in this series in a different monochrome colour and exhibited them in memory of his friend – who had died in 1974 – at the Galerie Heiner Friedrich. For this series, Knoebel developed a cutting technique: from painted paper sheets he cut forms out freehand with a cutter – a method that recalls Henri Matisse’s ‘papiers découpés’ – and then layered them one on top of the other. His use since the 1970s of the classic canon of red-yellow-blue (‘Messerschnitt Rot-Gelb-Blau’, 1978/79) allows us to read this as his coming to grips with the abstract-depictive possibilities of ‘Classical Modernism’, especially with the compositions of Piet Mondrian. Knoebel continued this series from the 1990s in the ‘Odyshape’ paintings (‘Odyshape C7’, 1995, ‘DIN XV Ci-C4’, 1995). Works such as ‘Ich nicht’, 2006 are an answer to Barnett Newman’s ‘Who’s Afraid of Red, Yellow and Blue’, 1966-67 and are the culmination of Knoebel’s occupation with an intense palette, whereby he – in contrast to Newman’s anti-compositional painting – still follows the laws of harmony in composing his colour fields and thus, according to Newman, rejects the experience of transcendence, i.e., that which rises above familiar experience. If Knoebel, similar to Mondrian, balances out the colours in his compositions according to the way they mutually push forward and recede back, ‘Ich nicht VII’ approaches Newman’s demand for a colour-filled painting: yellow is transformed into its own ‘differentiated energy field’.
The evolution Knoebel went through as an artist was carried out within the force field of Beuys’s position, the abstract potential of ‘Classical Modernism’ and the artistic currents of the 1960s. Knoebel saw his interest confirmed in purism and a reduction of the forms by the Minimalism of the Sixties and by the ‘pure art’ of Malevich. Like him Knoebel wanted to free the artefact from any references to figurativeness so as to achieve the spiritual emotion of non-representation. The development in the paintings of these past years, which show an increased tendency to the spiritual emotion of non-representation, point to the ‘initial meaning’ that Malevich had assumed for Knoebel. By transforming the real room into the picture world he goes beyond the easel painting, unlike Malevich, and occupies new aesthetic spaces. Knoebel’s feel for spatial situations and references, formal contexts and proportions has been marked to a great extent by the back and forth dialogue with his long-time teacher. In confrontation with the mythical-magical and socially utopian world of Beuys, his purist concerns were, on the one hand, reinforced as an anti-position. On the other hand, Beuys’s way of working and approach inspired him to a new interpretation of the emptied formalist vocabulary of Minimal Art and a critical questioning of the expressive capability of abstract ‘Classical Modernism’.