Take some long slender pieces cut from a board.About the size of a common yard stick.Taper one end down to a point.Not sharp though,so it won't damage a hide.When you put a skin on your stretcher to dry,slide this up along the belly,with the edge against the stretcher and skin.When the hide is dry,or ready to be flipped fur out,slide this stick out and it makes the hide loose on the stretcher.They can be a pain to get off without this sometimes.Unless, of course,your stretchers are hinged at the nose.Then never mind what I just said.