Acid-free paper

"♾" redirects here. For the infinity symbol, see ∞.
The acid-free-paper symbol;
U+267E ♾ PERMANENT PAPER SIGN

Acid-free paper is paper that, if infused in water, yields a neutral or basic pH (7 or slightly greater). It can be made from any cellulose fiber as long as the active acid pulp is eliminated during processing. It is also lignin- and sulfur-free.[1] Acid-free paper addresses the problem of preserving documents and preserving artwork for long periods.

  1. ^ "The Deterioration and Preservation of Paper: Some Essential Facts". The Library of Congress. Retrieved October 22, 2021.