Nano Silk is an amazing fly tying silk. Made from Gel Spun Yarn, (gsp) is the strongest fly tying yarn you will find for its diameter We use the 3/0 yarn for predator and sea fishing patterns. It is ultra strong and designed for those large flies! This incredible 200D material has a breaking strain of over 7Kg almost 15lbs. The white is dyed using permanent marker pens very easily to match any colour head required.