WonderFil InvisaFil Specialty Thread, 2-Ply Cottonized Soft Polyester, Silk-Like Thread for Fine Sewing, 100wt - Black, 2500m The InvisaFil Specialty Thread is the finest thread line from WonderFil. It is a silk-like 100wt, 2-ply cottonized polyester. Ultra-fine thread creates super low bulk stitches and virtually disappears. Crafted for whenever you want to hide stitches, such as English paper piercing, delicate lace designs, and fine fabrics. Fine thread is surprisingly strong in addition to being cotton-like with negligible stretch. Enjoy the soft feel of this silk-like thread for stitches that are hardly noticeable. Available in a wide variety of colors, from subtle to bright with matte finish. Choose a color for any occasion, you decide how much you want the thread to show (or not at all). Suggested uses include: stitch in the ditch, top and bottom thread, bottom thread for delicate machine embroidery, hand and machine appliqu, free motion quilting, stippling, English paper piecing.