Well, the beginning is actually quite easy, because I can still be quite free about the way I handle things - colours, shapes. And so a picture emerges that may look quite good for a while, so airy and colourful and new. But that will only last for a day at most, at which point it starts to look cheap and fake. And then the real work begins - changing, eradicating, starting again, and so on, until it's done.

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 first came up with the idea for the colour-chart pictures back in 1966, and my preoccupation with the topic culminated in 1974 with a painting that consisted of 4,096 colour fields. Initially I was attracted by the typical Pop Art aestheticism of using standard colour-sample cards; I preferred the unartistic, tasteful and secular illustration of the different tones to the paintings of Albers, Bill, Calderara, Lohse, etc.

Only about one per cent of my paintings show family members. Do they help me deal with problems? It's likely that these problems can only be depicted. But photographs, private ones and others, keep appearing that fascinate me so much that I want to paint them. And sometimes the real meaning these images have for me only becomes apparent later.

Pictures are the idea in visual or pictorial form; and the idea has to be legible, both in the individual picture and in the collective context - which presupposes, of course, that words are used to convey information about the idea and the context. However, none of this means that pictures function as illustrations of an idea: ultimately, they are the idea. Nor is the verbal formulation of the idea a translation of the visual: it simply bears a certain resemblance to the meaning of the idea. It is an interpretation, literally a reflection.

My paintings are wiser than I am.

Above all, it's never blind chance: it's a chance that is always planned, but also always surprising. And I need it in order to carry on, in order to eradicate my mistakes, to destroy what I've worked out wrong, to introduce something different and disruptive. I'm often astonished to find how much better chance is than I am.