Elongated tool (approx. 20 cm long; approx. 2 cm wide) usually made of bone, but possibly also horn, wood or ivory with rounded edges. One short side is more pointed than the other. It is used by the bookbinder and printer to flatten the corners and edges of the cover of a book and to press the crease in the spine. It is made of bone because this material does not leave a permanent crease mark in the paper or leather.