A great way to add texture to any sewing project! Special polyester thread that sews like normal thread, but when the wrong side of fabric is steamed with a hot steam iron, the thread shrinks 30%, leaving behind a beautiful shirred effect similar to smocking. For the best results, you can use the shrinking thread in the bobbin and the top thread. This thread is washable and it will work best on lightweight fabrics and quilting cottons. Incredible Shrinking Thread, 328 yard spool.