UNI-Threads are the favorite fly-tying threads of fly - tiers all over the world. Noted for being exceedingly strong for its diameter.
UNI-Thread is made of continuous polyester filaments, slightly bonded, which ties flat on the hook. 3/0 thread is good for bigger flies. 6/0 thread is good for big and middle sized flies. 8/0 is nice all-around thread for smaller flies. 3/0 has stregth of 266 deniers, 6/0 is 130 deniers and 8/0 is 71 deniers.
6/0 ja 8/0 spools are 200 yards (ca. 182 metres). 3/0 spools has 100 yards (ca. 91 metres).