I'm with Sagefisher on this one all the way. If the line I buy doesn't have a loop, I make one by whip finishing a thread wrap and giving it a coat of Goop or some other water resistant adhesive. This makes changing leaders on the water a snap and most of the time the loop lasts the entire life of the flyline. On the rare occasion when a flyline cracks right behind the loop ( usually after 2-3 seasons of use), then I simply make another loop. This has worked great for me for the past 15+ years.

Jim Smith