A recommendation that I would suggest, after you have fleshed it, you need to thin it a lot. You almost need to get to the point where you can see hair follicles from the flesh side. Remember that you are only braining it from the flesh side, so you don't have brain penetration from the hair side at all. With bison, if you are doing a robe thinning is essential also, but the fiber qualities of bison and cattle are completely different. The cattle fiber structure is really tight, compared to bison. In fact, bison are much more likely to start pulling apart if you over work the hide. Almost all of the old-time tanning recipes from American Indian women list grease or bone marrow grease as an ingredient. Neetsfoot oil is bone marrow grease, just as Knox gelatin is hide glue. Those old women were mixing the bone marrow grease with the brains to make their tanning solutions. I will tell you, you have your work cut out for you. Curtis