If you want the hide soft and pliable, you will need to tan it. If you don't tan it, you get rawhide, which is hard and stiff. It is used for drums, knife sheaths and a hundred other things, but for clothing, bags, etc., it needs to be tanned. How soft it gets is determined by how much you break down the cell structure during the tanning process. Brain tanning helps to soften the skin and then when breaking down the hide, it gets so supple that it's a pleasure to wear next to the skin. Brain tanned leather should be smoked too. It helps to keep insects away from the finished product and gives the hide a nice smokey color and aroma.
I should probably add an FYI here. Brain tanning means coming into contact with the tanning solution, which includes the brain matter. Because of the different diseases like Mad Cow, Chronic Wasting Disease and others that are killing off cattle, deer, elk, squirrels, etc., it could be hazzardous to your health. The cause of these diseases is a prion, which I believe is a protein of some kind. This prion doesn't ever die and can't be killed from extreme heat, cold or disinfection methods. So when you bring them into your home, you also take the chance of infecting your family. Little is actually known about them other than they exist and have been found in the infected critters and they eat gray matter and breed. Other than those two things, they really don't meet any other criteria of life as we know it. Anyways, that's what I learned several years ago from an article in outdoor life.
