Superior Threads So Fine! Straw 423 Poly 50wt is a high-quality 3-ply polyester thread designed for bobbin thread quilting and sewing. With a lint-free matte-finish smooth texture, this thread is perfect for blending and is popular among both longarm and home machine quilters. It also works exceptionally well as a bobbin thread. The 3280 yards of thread in a cone make it a long-lasting and versatile option for all your sewing and quilting projects.