SEMPERFLI NANO SILK 30 DENIER 18/0 For your smallest patterns where you want to build virtual no bulk. No need for different colors. Just take a marker to the thread, then coat with a UV resin, hit it with the light for a beautifully finished fly. Midges, dries, small nymphs, this is will be your new go to- and you can still split it down further or use it to tie dubbing loops. Recommended you use with ceramic bobbin. 50 yard spool.