I recently completed some buckskin leggins.  They are made from a brain tanned deer hide.  They have a slightly greasy feel to them, so I did not add anything to them.  I’m sure they will darken with use.  I got the hide from Wade Wagner at Rocky Mountain Robes & Braintan.  I made my fringes 6-7 inches long to match the description of P. L. Edwards, a layman in Jason Lee’s Missionary party.  In his letter dated June 23, 1834 he describes the fringed leather clothing of the mountain men: “You will perhaps recollect to have seen in the “far west” of our own United States, the buckskin hunting shirt and leggins gracefully hung with fringes along the arms and sides.  But I am sure you have never seen the tasty fashion of fringes carried to perfection.  Here they are six to seven inches long, and hung densely on every seam, I believe, both of the hunting shirt and leggins.”(The Rocky Mountain Journal of William Marshall Anderson, pg. 32)