I choose depending on the way I feel; randomly, in other words. When I haven't done anything for a long time, I always start small, on paper.

I like everything that has no style: dictionaries, photographs, nature, myself and my paintings. (Because style is violent, and I am not violent.)

Yes, we were amazed when that happened. It was a real joke to us. Konrad Lueg and I did a Happening, and we used the phrase just for the Happening, to have a catchy name for it; and then it immediately got taken up and brought into use. There's no defence against that - and really it's no bad thing.

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.

Painting is traditional but for me that doesn't mean the academy. I felt a need to paint; I love painting. It was something natural - as is listening to music or playing an instrument for some people. For this reason I searched for themes of my era and my generation. Photography offered this, so I chose it as a medium for painting.

As a matter of fact, it was only through the dealer Fred Jahn that I succeeded in overcoming my reservation about the works on paper and exhibiting them. Added to this, of course, was the fact that after ten years I could see the watercolours in a different light, and in conjunction with pictures painted afterwards, they had at least become more comprehensible to me.

And then the work bears a strong sense of leave-taking for me personally. It ends the work I began in the 1960s (paintings from black-and-white photographs), with a compressed summation that precludes any possible continuation. And so it is a leave-taking from thoughts and feelings of my own on a very basic level. Not that this is a deliberate act, of course; it is a quasi-automatic sequence of disintegration and reformation which I can perceive, as always, only in retrospect.