I'll second that. I was taught to tie it by the originator about 17 years ago and although Hans used elk hair to tie it he told me deer hair would work just as well. Just after starting to tie it I stopped in a fly shop, if I remember correctly in Willow Grove and got talking to the owner, Ken, I think. He told me if I was planning to tie a lot of deer hair caddis rather than buy the small patches of deer hair, buy a deer's mask. He sold me one for $10. Best $10 I ever spent on fly tying material.