Can't answer your question, but can tell my experience. I'm making 10-8-6 5 foot leaders with 4# Vanish using Kathy Scott's formula for the salt. I've broke off 1x Rio floro rated @13# three times. Twice on rocks and once on a fish. Looping a three-way swivel to the end and fishing two flies. Haven't had a problem with the leader breaking yet any way.