The finishing touches.
Binding can be loose-leaf with wire-o binding or spirals, Japanese binding, glued to the head, sewn with thread, or simply fastened with a staple in the top left corner. A cover may or may not be included, as you prefer. The interior can be folded into booklets and bound with thread in a soft cover or hard band. The latter option offers almost infinite possibilities as far as choice of materials is concerned, from leather to linen and from plastic to paper.