Photography has almost no reality; it is almost a hundred per cent picture. And painting always has reality: you can touch the paint; it has presence; but it always yields a picture - no matter whether good or bad. That's all the theory. It's no good. I once took some small photographs and then smeared them with paint. That partly resolved the problem, and it's really good - better than anything I could ever say on the subject.

I want pictorial content without sentiment, but I want it as human as possible

Painting is another form of thinking.

The photograph is the most perfect picture. It does not change; it is absolute, and therefore autonomous, unconditional, devoid of style. Both in its way of informing, and in what it informs of, it is my source.

But it is also untrue that I have nothing specific in mind. As with my landscapes: I see countless landscapes, photograph barely 1 in 100,000, and paint barely 1 in 100 of those that I photograph. I am therefore seeking something quite specific; from this I conclude that I know what I want.

It was not possible for us to produce the same optimism and the same kind of humour or irony. Actually, it was not irony. Lichtenstein is not ironic but he does have a special kind of humour. That's how I could describe it: humour and optimism. For Polke and me, everything was more fragmented. But how it was broken up is hard to describe.

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.