Cottage Mill® in BirchBirch is relatively rare, considering I only use naturally fallen tree branches, and Birch gets soft and punky quick, so I have to be luck enough to find it soon after it falls. I do remove the outer layers of the thin bark if, after I dry the wood, it separates, but if I can leave the bark on, I do. Some may have tiny "bubbles" of air under the remaining bark, but unless you put effort into removing the bark, it's 99. 9% stable. Birch is beautiful,