Why do newspapers fade and yellow within a few months?

Most commercial cellulose paper manufactured in the last century, including newsprint, is acidic. The acid makes paper brittle and eventually causes it to crumble with only minor use. The problem comes from two features of modern paper: the paper manufacturing process results in cellulose fibers that are very short and acid is introduced (or not removed by purification) during manufacture. Acid in the presence of moisture degrades the fibers, and the acidic reaction splits the cellulose chains into small fragments. The reaction itself produces acid, accelerating the degradation. Ironically, the older the paper the longer it lasts. Paper manufactured up until about the mid-nineteenth century was made from cotton and linen. These early papers had very long fibers, the key to their longevity. Today’s newspaper print is the weakest paper; it is unpurified and has the shortest fibers. Consequently, newspapers generally fade and yellow within a few months.