Thrums are small pieces of fleecy unspun fiber that you knit into your work to create a pattern on the right side, and warm, fleecy wrong side. These thrummed mittens are quick and easy to make, and have not thumbholes--your baby’s full hand will be encased in the wonderfully warm, fleecy interior. If you don’t have easy access to unspun fibers (known as wool tops--and you only need about an ounce worth), a loosely spun bulky yarn will do.