Question answered by: Penny and Michael Wayne
There are quite a few different processes in tanning, Chrome, Vegetable, Alum and Brain Tan. Chrome tan is made to be a weathered leather and is tanned with a chromium acid, so this will rust metals. Not a great leather for making gun and knife sheaths, it can be used but oil the leather well inside and out and don’t store metal objects for a long period of time. Vegetable tan is a natural tanning, this leather works for holsters and sheaths, also great for tooling, stamping, forming and dyeing. Alum tan is usually used for furs and hair on hides. Brain tan is an old way of tanning, it is using the brains of the animals. All natural and is used for beading and quill work.