tool
Bone folder
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. The folder from boxwood is mainly used
for folding sheets coming out of printing (1). The folder made of bone is
used by the bookbinder 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.
See also the paperknife and polishing bone. [MOT]