~ Cracked Spine Quick Fix: Joy of Cooking

There are two things to note in this video. The first is that this is a typical case-bound book meaning that the hollow spine area is a natural part of the construction. The second is that the reason this repair worked is that whenever you attach material like paper to an item with an adhesive, it creates a pull that forces the item to bend. The item in this case was the interior of the case-spine. What happens is that while you are gluing (or pasting) the paper the fibers of the paper are expanding and when they dry they contract and pull which creates the bend or curve. If we had wanted the spine to curve the other way we would have had to attach paper to the outside of the spine. Good thing that isn't what we wanted. The pull is also dependent on the grain of the paper. Make sure the paper wants to curl the same way you want the pages of the book to curl.

Correct Grain