Pages begin to tear loose from the binding and disintegrate into dust.
Undoubtedly, permanence of paper has long been recognized as crucial to library users who are concerned about access to vital legal information published in older materials. Leading surveys of library collections generally indicate that approximately three quarters of the books have acidic paper and two percent of the pages are very brittle. Indeed, crumbling paper is the main preservation problem in libraries today. Paper deteriorates from frequent use, becomes brittle and brown with age, and is affected by the chemical content of printing inks and writing materials. The primary cause of embrittlement is the acid hydrolysis of the main chain of the cellulose molecule.