In this video I briefly show how to extract fibers from the chaft of white-tail deer tendon. Sinew from many bovine animals produce the strongest natural fiber you can find. It is strong enough for use as bow-strings and backing bows for archery - a primitive form of fiber-glass. Sinew has natural glues that causes it to stick onto itself and shrink when dry. Although it is extremely tough and is used in a variety of ways like hafting stone tools onto handles, it is water-soluble and should not be left in the rain or allowed to soak in water for too long.
In order to render fibers from tendon all you need is a hard/semi-hard surface and a rock or mallet - wood or rubber would work.