There is one very simple thing I have never gotten the hang of during my 56 or 57 years of fly tying, ( depending if you want to actually call what I did the first year or two ‘tying’), and that is being able to “Consistently” snap tying thread without one of several problems occuring. Sometimes it leaves a tag or strand or fuzz of thread that has to be trimmed anyway or it will sometimes bend smaller hooks. Sure sometimes thread would break clean and shrink back properly and larger hooks wouldn’t bend but never could get it to do it consistantly. 6/0 and later, 8/0 thread is pretty much what I have always tied with. I guess having spent my working years as a splicer, then trouble shooter for the phone company I got use to holding scissors in my hand all during splicing and so when tying it was just as easy to hold scissor blade against taught thread as it was to learn the ‘consistent’ snapping of thread. Anybody got the answer or is it just me…Bob
I am a recent convert to snapping and since I usually tie stuff below size 16 I’m almost always using small hooks. The only time I may have a problem is when I’m using unbonded nylon thread like 70 denier Ultra Thread; sometimes I get the fuzz of thread thing. The problem is almost non-existent when I use regular polyester bonded thread like 8/0 Uni.
I think it may be that like me at times you don’t snap the thread quickly enough. I believe it’s more about the speed than the pressure because if I screw up a snap; I try again with a quicker snap and it usually goes fine. Right now I am tying #24 midges on Daiichi 1180’s and the 70 denier nylon is snapping like a football player’s hamstring with no bent hooks.
What I dont understand…
Is why snap the thread… Yes it may work 90% of the time… but why??
is the problem holding the scissors while tying?? is it faster then scissors?
As for as me I do neither… Id rather use finger nail clippers… small, compact, and has a very shape edge… all I do is “touch” the clippers to the thread and they cut it… no fuss, no mess…
but this is just my opinion…and we all know about that
Leonard:
For me it’s just a quicker way to get rid of the thread tag. I can’t get comfortable holding a pair of scissors in my hand at all times and stopping to pick up a pair to cut off the tag is just another step in the process I can eliminate by snapping; which works for me 99% of the time.
I use scissors that I keep on my table. Its a ritual like ribbon cutting and denotes a finished fly.
I like fly tying so I don’t rush and the number of flys I tie is unimportant. If I actually complete a fly then its a bonus 
Well said fishyfranky.
I’m a much better Fly fisher when talking fishing, than when I’m Actually Fly fishing!
I always snap the thread off when applying it to the hook. It just seems more efficient than scissors even with them in hand. For the finished fly I put tension on the thread and then cut it (no snip) with scissors.
Jay
Like you, I keep sissors in my hand during the entire tying procedure. I do have a cutting edge filed on the opposite end of my whip finisher (at end of handle) that at times I will cut the thread after completing the whip finish. No particular reason for this, just something I read about and wanted to try. It works fine and may save a little time but not that much. When I am tying I am not trying to save time. Tying is for relaxation and time to be creative.
Warren