Fore-edge painting

The Boston Public Library has launched a new online exhibition. On the Edge - The Hidden Art of Fore-Edge Painting.
Fore-edge painting is where an image is painted on the fore-edge of the book. When the edges are fanned the image appears. When the book is closed the image disappears.



We have a number of fore-edge paintings in the collections, although there are only a few listed in the catalogue. Is this a case where cataloguing our older collections with the item in hand may mean we miss some fore-edge decorations? Unless we fan the item, would we know? Would the catalogue card be annotated?
We certainly haven't digitised images from any of our fore-edge paintings!