Add "fore-edge printing" to the collection of interesting things you can do with print.
Martin Frost, who has produced more than 3000 such paintings since 1970, explains, "Unlike the spine and covers of a bookbinding, the page edges are not usually decorated, however…
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 refanned, the painting magically re-appears."
-- via neatorama
