Check the listing for details. UTC Ultra Thread 280 Denier Fly Tying Extra Thick Waxed Flat Jig Wrapping. Condition: New. Listed at 2.98 USD. UTC Ultra Thread Engineered as a fly tying thread from the beginning. It is not an “off the shelf” thread as are many others. All of Ultra Thread’s characteristics were carefully chosen to enhance its tying performance. Here are a few of the thread characteristics that make Ultra Thread ideal for fly tying: UTC chose nylon over polyester because nylon will stretch and grip materials better. More uniform tension and gives the tyer the “feel” for maximum tension. Nylon is the same strength as polyester (given the same denier) and offers the added benefit of more intense colors and a larger range of colors. Grips material tighter and makes the fly more durable. Thread is flat with only the minimum number of twists needed for production. The flatter the thread is wrapped, the more slowly it builds up. Grips and covers materials with fewer thread wraps. Lightly waxed. Low thread build up and for a smoother, slicker feel. Head cement fully penetrates the thread which equals more durable flies. Multifilament thread that is not bonded. Spools are sized and designed to turn smooth