My grandfather used to do a lot of leatherworking. It was a hobby of his. One thing he used to do a lot was use a series of dies and use them to press in on the leather and create designs in relief. By varying the pressure with which he pressed he could achieve amazing realism. I have several of his pieces that are cherished posessions of mine. One of them is a stallion rearing up on its hind legs in a western scene. I remember he used a single tear drop shaped die to slowly push in the entire design of the horse, and by varying the pressure he managed to create a beautiful impression of the muscles gliding beneath the horses skin. He really was quite an artist. He never sold a single one of his works, they were all gifts for others.