It's that same quality I've been talking about. It's neither contrived, nor surprising and smart, not baffling, not witty, not interesting, not cynical, it can't be planned and it probably can't even be described. It's just good.

The grey paintings, for example, a painted grey surface, completely monochromatic - they come from a motivation, or result from a state, that was very negative. It has a lot to do with hopelessness, depression and such things. But it has to be turned on its head in the end, and has to come to a form where these paintings possess beauty. And in this case, it's not a carefree beauty, but rather a serious one.

Experience has proved that there is no difference between a so-called realist painting - of a landscape, for example - and an abstract painting. They both have more or less the same effect on the observer.

When I look back on the townscapes now, they do seem to me to recall certain images of the destruction of Dresden during the war.

I find the Romantic period extraordinarily interesting. My landscapes have connections with Romanticism: at times I feel a real desire for, an attraction to, this period, and some of my pictures are a homage to Caspar David Friedrich.

The first colour charts were unsystematic. They were based directly on commercial colour samples. They were still related to Pop Art. In the canvases that followed, the colours were chosen arbitrarily and drawn by chance. Then, 180 tones were mixed according to a given system and drawn by chance to make four variations of 180 tones. But after that the number 180 seemed too arbitrary to me, so I developed a system based on a number of rigorously defined tones and proportions.

Turning to the colour-classification methodology: The starting point are the four pure colours red, yellow, green and blue; their in-between shades and scales of brightness result in colour schemes containing 16, 64, 256 and 1,024 shades. More colours would be pointless because it wouldn't be possible to distinguish between them clearly.