Originating in Newfoundland and Labrador Island, thrummed mittens are a fun way to create wonderfully warm, fleece- lined mittens. Thrums were originally scraps of yarn leftover from weaving projects, but now roving (tufts of unspun wool) is used. Roving thrums are added every 4th round to create that layer of wool insulation that felts with use. Be sure to use a yarn and fiber that has not been given a superwash treatment, because this project requires felting to create that firm lining.