Anthropodermic bibliopegy is the practice of binding books with human skin:
“Such volumes are the Hannibal Lecters of cultural objects…There is the whiff of the occult about them, but also of the slaughterhouse. It is the twinning of the human hide (more graphic evidence of death and bodily obliteration would be hard to find) with that most potent symbol of human culture and learning — the book — that creates a dissonance at once fascinating and repulsive.” [Source]
The above images show Leonard Smithers’s edition of Hans Holbein’s Dance of Death bound in human skin. Smither’s owned a vast collection of books and this particular entry, entitled “Human Skin Binding,” is described thus in his catalogue:
The front cover of the binding, in human skin, is inlaid in orange, red, brown, white, green, yellow, and purple leathers; the back cover, in human skin, is in red, brown, green, white, yellow and pink inlay; and the double in dark brown morocco shews a crimson inlaid Gallic devil, with a ghastly grin on its white skull, dancing and beating a yellow and white tambourine.”
Human skin binding is not as rare as one might think, it has been practiced on and off for hundreds of years, often using the skin of criminals and often, as here, to bind books which might seem particularly appropriate.