Bookworms were a problem in the Middle Ages, but a decent vellum parchment could last 300 years.

FORBES: Lucretius's Legacy Depended On The Toughness Of Vellum. What Will Save Ours?

Conservationists working in a new branch of the library still face the task of removing ash deposits between pages, repairing parchment volumes and vellum spines that split in the fierce heat a painstaking process that involves weeks of work on each book.

ECONOMIST: The Duchess Anna Amalia library