Madeira Polyneon #40 5500YD / 5000M Large Cone - 1621 - Rust. Madeira's 100% polyester embroidery thread, Polyneon is constructed of a specially developed raw material which eliminates looping, puckering and virtually all thread breaks.??? Suitable for almost any application, Polyneon's unique formula makes this thread extremely durable and smooth running.??? Vibrant colors, are glossy, as well as resistant to chlorine bleach, making Polyneon the ideal thread for embroidering on uniforms, safety garments and commercial linens. ???