Thin Skin is a .004 thick, stretchable and transparent sheet material that has a matte finish on one side and a shiny finish on the other. It is backed with a paper backing which makes it easy to cut into strips of all sizes. When the paper is removed, the transparent sheet can easily be tied onto the fly.The printed patterns on our Thin Skin can create an extremely realistic and/or dramatic look to the fly. Because Thin Skin stretches and compresses when thread or wire is wrapped around it, it is an ideal material to use for shellbacks on flies such as scuds or sowbugs or for wing cases on nymphs of all types. Many bass and saltwater fly tyers often use it to tie segmented crayfish and shrimp patterns. Awesome for wing cases and shellbacks. Easy to use and super durable.