Mettler PS8-KIT PolySheen Embroidery Thread Spools (Set of 8), 1500 yd/1372m, Excellent embroidery and decorative sewing, with no risk of thread breakage and can also be used with the latest high performance machines Poly Sheen has better elastic qualities and 50% higher tensile strength than rayon and can be used in every situation Well suited for use with highly stressed textiles such as sports and leisurewear, children's clothes, leather, work clothing, jeans, terry cloth, catering and hospital laundry