Slow fire

A book printed in 1920 on acid paper that is disintegrating.

A slow fire is a term used in library and information science to describe paper embrittlement resulting from acid decay. The term is taken from the title of Terry Sanders's 1987 film Slow Fires: On the preservation of the human record.

Solutions to this problem include the use of acid-free paper stocks, reformatting brittle books by microfilming, photocopying or digitization, and a variety of deacidification techniques.