I've never found anything to be lacking in a blurry canvas. Quite the contrary: you can see many more things in it than in a sharply focused image. A landscape painted with exactness forces you to see a determined number of clearly differentiated trees, while in a blurry canvas you can perceive as many trees as you want. The painting is more open.

Painting pictures is simply the official, the daily work, the profession, and in the case of the watercolours I can sooner afford to follow my mood, my spirits.

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.

The paint for the grey paintings was mixed beforehand and then applied with different implements - sometimes a roller, sometimes a brush. It was only after painting them that I sometimes felt that the grey was not yet satisfactory and that another layer of paint was needed.

I didn't actually know what the protesters in the West really wanted. It was fantastic here, so much freedom, and that was what they were calling musty, middle-class, and fascistic, a bleak period. Bleak was what the GDR was, and it alone had adopted, almost unchanged, Nazi Germany's methods of intimidation and ideas about propaganda and the use of force.

I am ridiculously old-fashioned.

I believe that you always have to believe. It's the only way; after all we both believe that we will do this exhibition. But I can't believe in God, as such, he's either too big or too small for me, and always incomprehensible, unbelievable.