This bone folder is actually made from an acrylic polymer. The reason it is called a bone folder is "two-fold" (heh, heh). First, they are used to aid in folding leather and pressing leather around a mold for custom fitting. Second, they used to be made from bone. You can actually still get them in bone. I chose this one because it has the added tool on the end (the large half-circle part) that has grooves and ridges used to crease lines and burnish the edges of a piece of leather. I just can't resist and nifty "two-in-one" tool!