I got this tip from a professional tier, Doug Hodges, now retired. He put a
tiny piece of the outside rubber coating of electrical wire on his bobbin
tip. Then would slide that up and over the end of his deer hair bullet head.
It would hold the hairs down perfectly and he'd tie them down, then slide
the rubber "o" ring back over the end of his bobbin, whip finish and tie
off. I find that a piece of a red rubber catheter size 8 French works great
for this. You can also use it to slide over the eye and back to hold back
extra hackle fibers when you tie dry flies. Joyce
