Liber Florum
The would-be reader of the Liber Florum is well advised to not touch any copy of this book with their bare hands. This includes modern facsimiles, although it’s apparently safe enough to handle individual pages that have not been not bound in any way, up to and including sheet protectors in a three-ring binder. That’s how people know that the book is magical, by the way. And apparently actively malevolent.