... -free) may be applied to spun polyester thread to enhance the sewing performance for specific applications. Spun polyester threads provide superior strength and are ... as heavy as denim. Specification: 20S/2, 20S/3, 30S/2, 30S/3, 40S/2, 40S/3, 50S/2, 50S/3, 60S/2, 60S/3 polyester sewing thread