There are many different fly tying threads on the market. Each has its own benefits, however strongest of all of these when comparing Uni, Roman Moser and Veevus is Semperfli Nano Silk which is 3 times stronger than any competitors. GSP Threads are extruded polyethylene made like spaghetti, however its makeup means that retention of colour is difficult. Flies should be tied them barnished to retain the colours. Personally we use the white threads then dye the last 4 inches of thread with permanent marker pens before we whip finish!
Our Favorite Semperfli Nano Silk
A fly tying silk which is virtually unbreakable, so we decided to do a little experiment. We got size 8 hooks in standard wire guage from a quality hook manufacturer, we twisted some Nano Silk around the hook , spun it then pulled. Even Sandy was surprised at the results, we managed to break the hook 3 times on the trot and had great fun proving that Semperfli Nano is amongst the strongest fly tying silks in the world. We love it for extra small dry flies as there is no build up from this stunningly thin 12/0 silk and for large Pike flies pull it tighter than any other silk to flare out Bucktail to produce amazing Octopus Pike flies.