On the Edge is Cool Site for May 2009

On the Edge: the Hidden Art of Fore-Edge Book Painting highlights a special collection of more than 200 high-resolution images of fore-edge paintings housed in the Rare Books Department of the Boston Public Library.
A fore-edge painting is where the page block is fanned and an image applied to the stepped surface. If the page edges are themselves gilded or marbled, this results in the image disappearing when the book is relaxed. When re-fanned, the painting magically re-appears.
Access the site here!