I did a leather bar wrap with hemp (because it lasts longer than cotton, flax, jute, or synthetic) twine, then Shellacked the whole thing about 10 years ago or more and the Shellac has held up fine. Of course you don't shellac leather because it won't work right so I did the twine and simply wrapped painters tape around the leather to prevent the shellac from getting directly on it. Also with shellacking the more coats you put on the darker it gets, so you simply stop shellacking when you reach the desire darkness.

I learned to do this by watch this video: http://www.rivbike.com/product-p/twine.htm Only difference is my twinning came out tighter packed then what the Rivendell guy did.