By far one of my favorite threads for nymphs and dry flies. Without a doubt this is the strongest thread on the market for its size and will keep the body of any nymphs and dries slim and non bulky.

Here is what semperfli has to say- "Nano Silk Ultra 30D 18/0 Black is considered the professional level being the finest of the range. 30d is also known as 18/0 – that is really very small fly tying thread. Nano Silk Ultra 30D 18/0 Black has all the strength you would expect from this premier thread. It is 10 times stronger than steel of the same diameter! Nano Silk Ultra 30D 18/0 Black is fine enough for size 16 to 32 flies whilst still retaining its strength. Although Nano Silk Ultra 30D 18/0 Black is a fine thread it can be split down further if required so dubbing making dubbing much easier!”