A Blow Book is a sophisticated version of The Magic Coloring Book. In its simplest form, every other page is cut short. So, like a Svengali Deck, when you riffle through the pages in one direction, only every other page is seen. When you riffle in the other direction, the opposing pages are seen.
A Blow Book works the same way, except that there can be five to ten different cuts along the edges of the pages, and by placing your thumb on the correct spot, you can show every ONLY fifth page or so.
Ricky Jay did a very fancy deluxe book on the subject, released through the Whitney Museum for over $1000 some years ago. Two volumes came in a clamshell box, one a blow book done using images by famous contemporary artists (William Wegman among them), the other book a history of the blow book by Jay. Now sold out and impossible to obtain.