I vaguely recall news about an artistic installation with a huge (3 or 4m square, probably painted polythene sheet) "negative" placed on a trimmed lawn for a few days for an event opening (was it Wimbledon?). It wasn't exactly a continuous-tone image though, and apparently disappeared very quickly.

This has been done for years on people hasn't it? With those little bunny-logo stickers . . . maybe I've been on the wrong beaches. . .