Some thoughts about Fly Tying Thread

I have been tying for a lot of years. Threads were terrible when I was a kid…they would break regularly.

In recent times, I have become enamored with GSP threads…get spun thread. Super strong…very hard to break unless you hit the tip of the hook when wrapping.

Roman Moser in Europe was the first guy to market this back in the 80s….he called it Power Silk..was a game changer for me tying small trout flies. GSP is now very available and much less expensive.

The only downside…it is slick..and it is a wee bit more difficult to cut. When starting the thread on a hook…the GSP needs a few more locking wraps due to its slickness..to lock the thread to the hook. Either super sharp scissors or a razor blade will easily cut the thread after whip finishing.

The super strong GSP threads are a game changer for fly tying. I highly recommend them. Be sure to use a ceramic tip bobbin..the cheap metal bobbins will get grooves due to the thread strength.

The real beauty of the stronger thread..you can use a smaller diameter strong thread so a few extra wraps does not build extra bulk.

Regarding denier vs the old size system.

6/0 is roughly equivalent to 150 denier—use for hooks over size 12

8/0 is roughly equivalent to 100 denier—hook size 12 to 14

12/0 is roughly equivalent to 50 denier—hook size 14 to 18

18/0 is roughly equivalent to 30 denier—hook size 18 to 20

24/0 is roughly equivalent to 20 denier.—hook size 20 and smaller

For practical tying, 8/0 or 100 denier is a good place to start. If you start with a GSP…this is a very strong thread that you will likely not break. Good for most flies including streamers, dries and nymphs down to size 14.

For flies smaller…go to 70 denier…

For tiny flies…go to 50 or smaller denier. For the very tiniest flies… Nano Silk in 20 denier will not build any bulk.

Semperfli has some lovely Nano Silks…I highly recommend them. They also split just fine for split thread dubbing techniques. If the smaller threads are only available in white or black…color the white with permanent markers…easily done while tying.

Another excellent thread is UTC Ultra Thread in 70 denier. This thread splits beautifully, and is available in a wide range of colors.

Start your selection with one or two spools…100 denier is a good place to start..more less the same size as 8/0. Black is fine to start.