Another trivia question is about why paper yellows and becomes more fragile. Paper came to be made out of wood pulp, a mix of cellulose and lignin. Both can oxidize a bit and therefore, discolor. Acid-free paper which lasts longer for more important documents has much less lignin in it. They do not deteriorate so quickly. To learn more about the history of how paper came to be and how it is made can be noted here.

Tags: Trees, Trivia