ISO 3135:2025

Marking pens - Durability of written line - Documentary use (DOC)

This document establishes minimum quality requirements for durability of written line with marking pens for documentary use.

Titre manque

General Information

• Status: Published
• Publication Date: 27-Apr-2025
• ICS: 01.100.40 - Drawing equipment
• Technical Committee: ISO/TC 10 - Technical product documentation
• Drafting Committee: ISO/TC 10/WG 18 - Drawing and writing instruments
• Current Stage: 6060 - International Standard published
• Start Date: 28-Apr-2025
• Due Date: 12-Dec-2025
• Completion Date: 28-Apr-2025

Overview

ISO 3135:2025 - Marking pens - Durability of written line - Documentary use (DOC) defines minimum quality requirements and test methods to ensure marking-pen writing is durable and suitable for documentary use. The standard specifies how to evaluate resistance of the written line to physical, chemical and environmental stresses so that documents remain legible, tamper-evident and reproducible over time.

Key topics and technical requirements

• Scope: Establishes minimum durability criteria for marking pens intended for documentary use (DOC).
• Durability tests: Written lines are evaluated for:
  • Water resistance (immersion for 24 h)
  • Ethanol resistance (50% aqueous ethanol, 10 min)
  • Hydrochloric acid resistance (10% HCl, 24 h)
  • Ammonium hydroxide resistance (10% NH4OH, 24 h)
  • Bleaching resistance (3% chloramine T, 5 min)
  • Erasure resistance (use of a specified eraser; line must remain until paper shows damage)
  • Light resistance (xenon/fade test using ISO 105-B02 and ISO 105-A02 reference scale)
  • Reproducibility (legibility of photocopies/facsimiles)
• Test materials & apparatus: Includes prescribed performance testing paper (per ISO 12757‑1 / ISO 14145‑1 / ISO 27668‑1), eraser hardness (45 ± 5 Shore A per ISO 868), light test equipment (Fade‑o‑meter / xenotest) and test solutions (specified concentrations).
• Sampling & conditions: Samples tested within six months of manufacture under a standard test atmosphere (specified temperature and relative humidity).
• Marking: Pens compliant with ISO 3135:2025 must be marked with manufacturer/trademark, a DOC indicator, and date-of-manufacture or batch number.
• Test reporting: The standard requires documented test procedures and results to support conformity.

Applications and users

Who benefits from using ISO 3135:2025:

• Marking-pen manufacturers - to design and certify pens for archival and documentary markets.
• Quality and compliance teams - to set acceptance criteria and supplier specifications.
• Testing laboratories - to perform standardized durability and reproducibility testing.
• Archivists, records managers and legal authorities - to select pens that preserve legibility and resist tampering for evidence, records and long‑term storage.
• Procurement specialists - to specify documentary-use (DOC) pens in contracts and purchases.

Practical uses include signing legal documents, archival labeling, evidence documentation and any application where long-term legibility, tamper resistance and reliable reproduction are required.

Related standards

• ISO 105-A02 (grey scale for colour change)
• ISO 105-B02 (colour fastness to artificial light / xenon arc)
• ISO 868 (Shore hardness)
• ISO 12757-1, ISO 14145-1, ISO 27668-1 (testing paper and pen families)

Keywords: ISO 3135:2025, marking pens, durability of written line, documentary use, DOC, water resistance, light resistance, erasure resistance, reproducibility, archival ink standards.

Standards Content (Sample)

International
Standard
ISO 3135
First edition
Marking pens — Durability of written
2025-04
line — Documentary use (DOC)
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 Water resistance .2
4.2 Ethanol resistance .2
4.3 Hydrochloric acid resistance .2
4.4 Ammonium hydroxide resistance .2
4.5 Bleaching resistance .2
4.6 Erasure resistance .2
4.7 Light resistance .2
4.8 Reproducibility . .2
5 Test equipment and accessories . 2
5.1 Performance testing paper .2
5.2 Eraser .2
5.3 Light test apparatus .2
5.4 Reproducibility apparatus .2
5.5 Test solutions .3
5.5.1 Ethanol solution .3
5.5.2 Hydrochloric acid solution.3
5.5.3 Ammonium hydroxide solution .3
5.5.4 Bleaching solution .3
6 Testing. 3
6.1 Sampling .3
6.2 Climatic conditions for testing .3
6.3 Procedure .3
6.3.1 Preparation of test piece .3
6.3.2 Water resistance test .3
6.3.3 Ethanol resistance test .3
6.3.4 Hydrochloric acid resistance test .3
6.3.5 Ammonium hydroxide resistance test .4
6.3.6 Bleaching resistance test .4
6.3.7 Erasure resistance test .4
6.3.8 Light resistance test .4
6.3.9 Reproducibility test .4
7 Marking . . 4
8 Test report . 4
Bibliography . 6

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www
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