Guterman Extra Strong 100m, Colour – 369, 2T100E369. The Guterman Extra Strong Thread is ideal for heavy duty uses such as upholstery, vinyl, heavyweight fabrics, denim and leather. Featuring a high break point and made using 100% polyester, designed to cope with highly stressed seems. With its finer than the top stich threat it can be used for both hand and machine sewing. A size 100 universal needle or top stitch needle is recommended for use with this thread.