Sharkskin lines are produced with a microtextured surface that reduces friction on your rod guides and increases surface area on the water. The result is a better shooting, higher floating line. Also, the textured pattern releases water on the backcast, reducing water droplet splashing on your presentations. We have cast and fished these lines on our favorite rods. Honestly, we're very impressed. The Sharkskin GPX Taper is designed with the same basic proportions as the regular Mastery GPX Taper. This is a general presentation weight-forward line this is made 1/2 size heavier than the given line weight to load fast-action rods. The Sharkskin GPX is our best all-purpose trout line for fast and medium-fast action fly rods.