Leather Working Wisdom Edit
Enough Brains To Tan Your Own Hide
For anyone who has actually worked with hides, the most common bit of knowledge is that brains are the main component of creating a finished hide. Yes, brains. Boiling is actually a process to create a mixture used to tan a hide, not a process to complete a hide. Boiling can also be used after the process of tanning to cause a hide to become hardened. It is common-folk knowledge that every creature has enough brain matter to boil its own hide - you may have even heard that expression; this is the reason.
What are you doing when you use brains to tan a hide? Well, the mucus glands and such are a strong component of every skin, and unless you remove them/dissolve them, a hide cannot be truly tanned and made supple or hardy. You need to work the hide by stretching, pulling and cleaning off the residual skin and really kneading and working that hide! Once you've done that, you can then use your brain solution to penetrate the hide to make it both supple and long-lasting. Remember that we're talking about typical tanning processes of our early history, not modern petro-chemical alternatives you find nowadays.
Some other things you can do with hides is to "smoke" them (hanging them over the rafters for 6-12 months). You can add things to the brain solution: fats, yucca soaps, tannins (like wild rhubard!), ash and even cornmeal. Some native tribes used corn instead of brains.