Designed for Invisible appliqué and Quilting. This reduced-sheen monofilament polyester is the best choice when it comes to invisible threads. Unlike other monofilament threads made from nylon, MonoPoly is 100% polyester. Commonly referred to as an invisible thread due to its fineness and reduced-sheen, MonoPoly is great for the bobbin or top. Available in two colors, Smoke (for dark fabrics) and Clear (for light fabrics). MonoPoly is ideal for invisible appliqué and quilting when the stitching is not meant to be seen. MonoPoly is recommended over nylon monofilament threads because MonoPoly will not become brittle over time (nylon monofilament thread tends to go brittle), MonoPoly will not discolor (nylon monofilament thread tends to "yellow" over time), and MonoPoly is dryer and iron safe on medium heat.