Acid-free Paper - Archival Paper

Archival paper is an especially permanent, durable acid-free paper. Archival paper is meant to be used for publications of high legal, historical, or significant value. In the USA, such paper must also be approved in accordance with the ANSI standards. The international standard for "permanent" paper is ISO 9706 and for "archival" paper, the standard is ISO 11108.

Often, cotton rag paper is used for archival purposes, as it is not made from wood-based pulp. Thus, "archival paper" is sometimes broken down into two categories:

• Conservation-grade — acid-free, buffered paper made from wood-based pulp.
• Archival-grade (also Museum-grade) — cotton rag paper made from cotton pulp.