Valdani Perle Cotton Size 8 Joy to the World - 12 Balls A highly decorative, double-twisted, indivisible long staple made of 100% cotton with a silky lustre. These threads are ready for machine or handwork. Colorfast, 67m balls. Size 8 (medium weight) - For: Stitching, Hand Quilting, Appliqu, Crochet, heavier Punchneedle, Rug-Hooking, Bobbin Work.