Singer Polyester Hand Sewing Thread Spools I love to keep an eye out for fly tying materials in unlikely places. “Singer Polyester Hand Sewing Thread Spools” are available at drug stores and super markets for around three dollars. ... There is enough material for hundreds of flies. This material is excellent for slender bodies. It floats and comes in wonderful colors. I wind it around hooks to imitate the colors of baetis (Blue winged Olives,) Craneflies, Sulphurs, Adams, Henryvilles and many others.