Fortunately, the less you have to rely on art materials – what are considered classic art materials which are all overpriced anyway – the more you can rely on materials at large in the culture and the more you should rely on them. The more free you are because you're not tied down to a higher-priced set of materials. That's the advantage of getting out in to the streets. I find that work I'm interested in now is made out of things which have been discarded by people – metals and things which I find in vacant lots. I don't want all of it. I want only certain kinds for certain purposes. But this is of interest to me now, just so I won't get into a trap where I have to work and continue with more and more expensive materials.

p. 25 - 'Artists talks 1969 – 1977'