When I was in grade school we were allowed to go upstairs into the closed High School area on occasion. (It had been closed when they consolidated the small town schools into a northern county school.)
On occasion when going through the classrooms we were allowed to take any sundries that were still lying around. I got an old 1950s biology book and an older copy of Robinson Crusoe. The spine on the RC was split and on the inside of the spine was lettering.
To this day I am unsure if it was just due to reused paper (likely) or some hidden message from the publisher/printer....but it sure got a 11 year old boy’s minda goin’. :)
Latest Simon Parkes video, explaining the AT&T bombing. His information is that it was a black hat operation intended to destroy the archives that go back to mid 80s, and render the hardware useless. The operation was co-opted by white hats.
The video is about 1/2 hour long:
From Anonymous:
Ransomnote: Those are called fore-edge painting books.
Some more rare versions have paintings done both directions. One done with the pages bent in the jig one direction and a different painting done with the pages in the jig bent the opposite direction.
They have to be painted with a virtually dry brush.
foreedge.bpl.org
https://twistedsifter.com/2013/09/hidden-artworks-on-the-edges-of-books/
same as this link:
40 Hidden Artworks Painted on the Edges of Books ยป TwistedSifter
https://en.wikipedia.org/wiki/Fore-edge_painting
Fore-edge Paintings: Beauty on the Edge on AbeBooks
How to Add Your Own Hidden Fore-Edge Painting to Any Book (mymodernmet.com)
Some are also painted on the fore-edge without fanning them or gilding them.
(1) Pinterest
https://www.foreedgepainting.com/gallery