Today I am going to talk to you about the different types of tying threads out there for fly tying. The first thing we should go over is the sizes as they can be quite confusing to anyone starting out. There is two common size types of thread, a “zero” measurement system and the more standard sizing denier. The “zero” measurement system was originally used to measure silk thread a long time ago. Unfortunately it is a more archaic system and not as reliable as the denier s