Permacore® Tex 40 is 100% corespun polyester wrapped thread. Its polyester wrapped construction provides more strength than cotton or polyester spun threads, so you can use a smaller stitch size without sacrificing the strength of your seams. Permacore® offers a beautiful sheen, excellent sewability, and reduced seam pucker. Ideal for sewing anything from light weight garments such as blouses or shirts to heavy garments such as jeans or coveralls. Each spool contains 6000 yards.