Limp binding is a bookbinding method in which the book has flexible cloth, leather, vellum, or (rarely) paper sides. When the sides of the book are made of vellum, the bookbinding method is also known as limp vellum.
The cover is made with a single piece of vellum or alternative material, folded around the text block, the front and back covers being folded double. The quires are sewn onto cords such as alum-tawed thongs and the sewing supports would be laced into the vellum cover. The thongs would also often be used at the fore edge of the covers to create a closure or tie.
In limp binding the covering material is not stiffened by thick boards, although paste-downs if used, provide some stiffness; some limp bindings have only adhered to the back of the book.Some limp vellum bindings had yapped edges that flop over to protect the text block.(wikipedia)
In this very description video tutorial you will be able to learn how to do vellum limp binding step by step in just 15 minutes, in this movie there is no narration or subtitle description but i tried to make it visually clear to all,so feel free to pause the movie and rewind it if you miss any part then play it back again several times until you completely feel that you have got the idea, try to find a good quality vellum material to try to do your limp binding otherwise you can use other limp materials such as cloth or leather or even good quality paper just to get practice on this binding technique..