Bone Folder

I think you may have forgotten to put in a link or something? :)
 
Bone folders have been used by we book binders for centuries. I got into book binding/restoring back in the '70s when I could only find a couple of fully stocked bookbinding suppliers in the country. I used to have two, but I only find my 8 incher right now. I believe the idea is to make a good and neat crease without leaving a shiny edge.

Wade