on a quick business trip to Alaska stopped at a fly shop to buy some needed tippet - they only had one brand and it wasn't Umpqua Broke off three 30" rainbows at tippet knots that trip. Never again bought that tippet. There are only two brands of fluoro tippet I'll use, and Umpqua is one of those. No question it has superior knot strength. The 27" 8-lb rainbow was on 5x Umpqua tippet, and a size 22 thread midge.