Wapsi Thin Skin is .004″ thick and can be used on flies past size 18. It is stretchable and transluscent with a matte finish on one side and a shiny finish on the other. The backing makes it easy to cut to width. Wapsi Thin Skin Gator was inspired by nature. Having the look of wing veins, it is perfect for stoneflies, dragon flies, damsel flies and hoppers.