Contact with like-minded painters - a group means a great deal to me: nothing comes in isolation. We have worked out our ideas largely by talking them through. Shutting myself away in the country, for instance, would do nothing for me. One depends on one's surroundings. And so the exchange with other artists - and especially the collaboration with Lueg and Polke - matters a lot to me: it is part of the input that I need.

Painting is another form of thinking.

The political topicality of my October paintings means almost nothing to me, but in many reviews it is the first or only thing that arouses interest, and the response to the pictures varies according to current political circumstance. I find this rather a distraction.

Almost every work of art is an analogy. When I make a representation of something, this too is an analogy to what exists; I make an effort to get a grip on the thing by depicting it. I prefer to steer clear of anything aesthetic, so as not to set obstacles in my own way and not to have the problem of people saying: 'Ah, yes, that's how he sees the world, that's his interpretation.'

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.

There was no special event that made me decide. I had collected some photos and the idea was in the back of my mind for a long time. It was growing and growing, so finally I said, 'I must paint this.' I come from East Germany and am not a Marxist, so of course at the time I had no sympathy for the ideas, or for the ideology that these people represented. I couldn't understand, but I was still impressed. Like everyone, I was touched. It was an exceptional moment for Germany.

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.