1. It starts with removing the excess flesh and muscle. This can be done by skinning the skull, but most of the time we let the bugs do the work by placing the skulls in an old chicken coop to protect them from predators and allowing the bugs to come in and eat the flesh off the bones for about a year. It is important that the skull have contact with the ground so it can interact with the bugs and microbes in the dirt.
2. After about a year we pull the skull out, separate the horn caps from the bone (at this point they should separate pretty easily), and then simmer the skull over low heat for about six hours. We also add a small amount of an enzyme basedlaundry detergent to help break down the tissues. The simmer is controversial as some producers believe that this makes the bones brittle. Bison bones seem to hold up well, but you do want to keep an eye on it and not cook them.
3. Next step: Pressure wash the skulls. You want to get down to the bone, you will notice that there is a thin layer of connective tissue that you want to wash off. Eye protection is recommended as the curvature of the bones will for sure send rotting boiled flesh back at your face.
4. Whitening. You can leave the skull out in the sun and do a sun bleach, which creates a nice natural finish. If you need to get the skull white faster, or want a more bleached look we use hair developer. Beauty supply stores sell hydrogen peroxide hair developer, we use the highest concentration we can find, typically 40%. Try to buy the liquid rather than the cream. We mix that with water in a wheelbarrow and submerge the skull/bones (not the caps) Let them sit until they reach your desired color. You can reuse the water/hydrogen peroxide mixture a couple of times but it does loose its potency after a few rounds.
5. Clean and polish the horn caps, we normally scrub with a wire brush and use linseed oil to polish. Then you can place or glue them back in place.