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. Uses include: Nymph Wing Cases and Backs for Scuds, Sowbugs, Crayfish and Shrimp. This assortment includes 8 different thin skins, both patterned and solids, in half size pieces. Ready to create flies!