The Primary Reason Why Old Newspapers and Books Turn Yellow With Age

In a recent episode of Today I Found Out, host Simon Whistler explains why old books and newspaper turn yellow with age using information from a post written by Matt Blitz.

.Lignin is a compound found in wood that actually makes the wood stronger and harder. "Lignin is a dark color naturally (think brown-paper bags or brown cardboard boxes, where much of the lignin is left in for added strength, while also resulting in the bags/boxes being cheaper due to less processing needed in their creation). Lignin is also highly susceptible to oxidation. Exposure to oxygen (especially when combined with sunlight) alters the molecular structure of lignin, causing a change in how the compound absorbs and reflects light, resulting in the substance containing oxidized lignin turning a yellow-brown color in the human visual spectrum.