I’ve been secretly vetting this thread for a couple years now and after using it extensively, I finally feel comfortable adding it to our shop selection and actually recommending it to my customers. I don’t take this lightly and wouldn’t point you to a tool or material that I hadn’t used so sometimes it takes a while.
Semperfli Nano Silk 18/0 is a 30 denier GSP thread (read that as super thin)that is incredibly strong (strong enough to flare deer hair on X-Caddis and Screaming Banshees) and build up virtually no bulk on the hook. Nano Silk lies very flat but doesn’t spread uncontrollably like most other GSP threads and the spools don’t get all ratted up over time, either. This is the best fine thread I have found and it works well on tiny dries, parachutes, thin midges (Jujubee) and anything else where you don’t want a bulky thread. The bonus that this stuff is super strong really changes the game. Get some of this right now. You’ll be glad you did.