Each piece is crafted by hand so even if the craftsman is following the same design, no two pieces will ever be exactly the same that include exotic inlays of shell or precious stones so as they really do represent superb artworks in miniature. They are often used in combination with leather and/or beads. Bone work must be tightly knit to offer the protection is was intended for. The addition of a centerpiece of carved bone adds significant value to the work. Smaller bone pieces generally require more work than larger pieces. Brown and black bone are generally more expensive than white. The longer the piece of bone, the more difficult it is to get and therefore more expensive. Horn bone is less expensive than internal bone.