Book preservation is an important part of preserving culture and ensuring education for future generations. Creasing is one of the most common ailments that befall books. Books crease from the pressure of other objects, or from people using folds as book markers. You can remove many creases from a book cover or its pages. Pressure is one common way to force a crease out of a page, while steam is another way.
Flatten the creased page with your hand, then close the book. If the book cover is creased, bend it back into place gently.
Close the book and place it flat on the table. Stack other books on top of it; the heavier the better. The pressure of the books will help to decrease the page or cover. Allow the book to sit there for three or more days. Check the book every day to see if the crease is still there.
Open the book cover or the page that is creased, and place it flat down on an ironing board if the stacking the book didn't remove the crease.
Set a thin towel on top of the creased cover or page.
Fill the iron with water. Turn the iron to the "Delicate/Silk" setting.
Press the steam button and hold the iron a couple inches from the page for three minutes. Allow the steam from the iron to remove the crease. Check the cover or page to see if the crease has been affected.
Set the hot iron directly on the towel. Move the iron from one side to the next once. Remove the towel from the book and check the crease. If the crease is still there, allow the cover or book to cool down, then try it again until the crease is removed. Keep checking to make sure you don't burn the book.