Why old books crumble at the slightest touch?

Librarians all over the world are facing a problem. They have begun to realize that practically all the books that were printed after 1850 are deteriorating rapidly.

What’s the reason?

Before the Chinese invented paper in 105 A.D., books were written on parchment – the skin of sheep or goats and vellum or calf-skin.

The Chinese made paper from mulberry fibre, fish-nets, old rags and waste hemp.

After 1850, the demand for paper increased so much that a low-cost substitute for linen and cotton rags began to be used. This was wood pulp. The drawback is that during processing, a number of chemicals are added to the pulp. These include acids. Over a period of time, these chemicals and acids eat away the paper. It starts yellowing and crumbling to dust at the slightest touch. Thus, ironically, books printed in the 1500’s are in a better condition today than books printed just 40 years ago! Saving these books is a tedious and expensive process, requiring each page to be treated to remove the acid.


Picture Credit : Google