Many occultists are bibliophiles. Some are focused on content, some on provenance, some on the exotic nature of the materials used in making a given set of books, or even – perhaps especially – one, particular unique tome. Unusual bindings seem to delight many: goat, toad, snake skin… and most intriguing, homo sapiens sapiens. HOWEVER, while there may be legends and rumors of the most deeply esoteric texts being bound in human skin, those who study anthropodermic books are of the opinion that the rumors of such books, on any topic, are severely limited, and none that have been authenticated are devoted to occult subject matter. Here’s a recent New York Times story on the subject:
https://www.nytimes.com/2024/04/19/arts/books-human-skin-harvard.html.