Last year in my spinning guild meeting we learned about "thrums" and how to use them to add insulation to our mittens. I decided to try this technique and made this pair of mittens.
The mittens are made from a hand spun dark grey Corriedale fleece that I purchased about a year ago. The pink stitches are made from unspun Merino fiber that is made into thrums. You can see in the basket the unspun pink fibers that are made into a bow by twisting the ends toward the middle of a 4 inch length of fiber.
I then knit these little bows into the work so that the ends remain loose on the inside of the mitten. These loose ends inside make a wonderful wool lining that gives added warmth to the mittens.
As you wear these mittens the friction from your hand causes the loose ends of the thrum to felt slightly, so the unspun thrums will not come out or fall apart.