Matt, The leather was stacked on an all-thread rod and clamped tight, then run through a stabilizing process by Ernie Grospitch. He has a tutorial on his stencil site. Blue Lightning I think. He sent me a chunk that he made and I cut it in half and drilled it like wood. It is flakier than wood but only slightly. Easy to broach or file. I don't recall what it is stabilized with but I would not mind if it was a little harder to bring it up to the hardness of most woods. That said, I am happy with it.