http://www.economist.com/books/displayStory.cfm?story_id=16213978.

“YVES KLEIN was lounging on a beach with some friends in 1947 when he had his big artistic breakthrough, so the story goes. Born in Nice to painter parents, the 19-year-old Klein gazed up at the sky and imagined signing his name near the clouds. “The blue sky is my first artwork,” he declared, neatly summing up his ambitions to breach the ordinary boundaries of art; no mean feat in post-war Europe.”