Waspi UTC Ultra Fly Tying Thread 140- This 140 denier Wapsi UTC Ultra Thread is a nylon material which lies relatively flat and is a good general purpose thread. It is a great thread for beginning fly tyers and is also used for the split thread dubbing technique. UTC 140 has a breaking strength of approximately 2lbs. and is recommended by Wapsi for size 6 to 14 flies. It has a slightly larger denier than the UNI 6/0 and Danville 3/0 threads.
UTC thread color chart.