ISO 11108:2025

Overview

ISO 11108:2025 - Information and documentation - Archival paper - Requirements for permanence and durability - defines minimum technical requirements for archival paper intended for permanent retention and frequent use. Applicable to unprinted papers for documents and publications with high historical, legal or cultural value, the standard specifies physical and chemical limits to ensure long-term chemical stability and resistance to wear. ISO 11108:2025 is the second edition and is intended for use by paper manufacturers, archives, libraries, museums and conservation professionals.

Key topics and technical requirements

The standard prescribes measurable characteristics and test methods (sampling and conditioning per referenced ISO standards). Key requirements include:

• Fibre composition: Principally cotton, cotton linters, hemp, flax, or mixtures; minor fractions of fully bleached chemical pulp allowed if declared.
• Grammage: Minimum 70 g/m² (no upper limit within ISO paper definition).
• Tearing resistance: ≥ 350 mN in any direction (Elmendorf method).
• Folding endurance: Minimum log-fold values - 2.42 (Schopper) ≈ 260 folds, or 2.18 (Lhomargy, Köhler‑Molin, MIT) ≈ 150 folds.
• pH of aqueous extract: 7.5–10.0 (cold extraction) and no single layer below 7.5.
• Alkali reserve: ≥ 0.4 mol acid neutralization per kg (≈ 20 g CaCO3/kg when calcium carbonate is used).
• Resistance to oxidation: Kappa number < 5.0 (measured per ISO 302 with ISO 9706 modification).
• Visual inspection: Free from obvious defects (creases, large specks, holes, wrinkles).
• Reporting: Test reports must identify the lot, give conditioning details, test results, observations and a statement of conformity or non‑conformity.

These tests reference ISO 186, ISO 187, ISO 302, ISO 536, ISO 1974, ISO 5626, ISO 6588‑1 and ISO 10716.

Applications and who uses it

ISO 11108:2025 is used to specify and verify paper for:

• Archival books, legal records, certificates and registers
• Library and museum documentation intended for indefinite storage and frequent handling
• High-value publications where long-term readability and durability are essential Primary users: paper manufacturers, procurement officers, archivists, conservators, records managers, printers producing archival editions, and standards bodies.

Related standards

• ISO 9706:2025 - Paper for documents - Requirements for permanence (permanence without the added durability tests).
• ISO 20494 - Paper stability for general graphic applications (service-life based approach for non‑permanent print).
• Other referenced test standards: ISO 186, ISO 187, ISO 302, ISO 536, ISO 1974, ISO 5626, ISO 6588‑1, ISO 10716.

ISO 11108:2025 helps organizations ensure that paper substrates meet strict permanence and durability criteria for long-term preservation and frequent use.