ISO 22785-4:2026

• Abstract:

  This document specifies the abrasion and scratch tests of coatings on plastics, plastics composites, and similar substrates, hereinafter collectively referred to as plastics. This document shows the potential effect of plastics on the behaviour of the coating during abrasion and scratch testing.

• Status: Published
• Publication Date: 02-Aug-2026
• ICS: 83.080.01 - Plastics in general
• ICS: 83.120 - Reinforced plastics
• ICS: 87.040 - Paints and varnishes
• Technical Committee: ISO/TC 35/SC 9 - General test methods for paints and varnishes
• Drafting Committee: ISO/TC 35/SC 9/WG 31 - Properties after application
• Current Stage: 6060 - International Standard published
• Start Date: 03-Aug-2026
• Due Date: 06-May-2027
• Completion Date: 03-Aug-2026

Overview

ISO 22785-4: Paints and varnishes - Coatings on plastics and composites - Part 4: Abrasion and scratch testing establishes internationally recognized procedures for evaluating the resistance of coatings applied to plastics and plastic composites. This standard is essential for industries where the durability and surface quality of coated plastics are critical, offering guidance on the unique characteristics of plastics compared to metallic substrates and how these differences impact test outcomes. Developed by ISO Technical Committee 35/SC 9, it covers both abrasion and scratch test methodologies, enabling reproducibility and accuracy in assessing coating performance.

Key Topics

• Scope and Purpose

  • Assessment of abrasion and scratch resistance in coatings on plastics and related composites.
  • Consideration of the distinct behaviors between plastic substrates and metals, focusing on elasticity, surface condition, and environmental factors.

• Test Sample Preparation

  • Emphasizes the importance of substrate condition, free from contaminants that could affect adhesion or long-term performance.
  • Outlines sample conditioning requirements, referencing ISO 3270 for standard climates and noting the longer conditioning times needed for plastics due to sensitivity to humidity.

• Main Testing Methods

  • Linear Abrasion: Uses a linear abrasion tester, with adjustable parameters for stress, friction path, and double strokes, accommodating different friction partners (e.g., textile, metal, abrasive paper).
  • Hand Abrasion: Simulates real-life wear from handling, deploying a silicone stamp and test fabric. Media such as sweat, cream, or detergents can be integrated to mimic actual use conditions.
  • Scratch Tests: Includes both manual (e.g., hardness pens, gash resistance testers per ISO 22557) and automatic options, employing standardized loads and friction partners for replicable results.
  • Rotating Abrasion: Supports additional methods like the Taber or Martindale tests for comprehensive evaluation.

• Evaluation After Testing

  • Recommendations for visual inspection, color measurement, gloss and haze evaluation, and mass loss calculation, ensuring a holistic understanding of coating performance.

Applications

ISO 22785-4 provides essential guidance for a wide range of industries focused on quality and resilience of coated plastics, including:

• Automotive: Testing interior/exterior trim parts, dashboards, and displays for abrasion and scratch resistance to ensure longevity and aesthetic appeal.
• Consumer Electronics: Evaluating coatings on device casings, screens, and buttons to maintain surface integrity under regular use.
• Appliances: Assuring the durability of visible plastic surfaces on household and commercial equipment.
• Industrial Equipment: Assessing coatings on plastic machine panels, covers, and user interfaces for repeated handling and cleaning.
• Medical Devices: Verifying that coatings on plastic medical equipment withstand frequent disinfection and handling without degrading.

By applying this standard, manufacturers can substantiate claims regarding surface durability, meet regulatory or client requirements, and compare results globally thanks to ISO harmonization.

Related Standards

Organizations implementing ISO 22785-4 should also consider the following:

• ISO 4618: Paints and varnishes - Vocabulary: Establishes terminology used throughout the industry for clear communication.
• ISO 22785-1: Coatings on plastics and composites - Part 1: General introduction: Provides foundational concepts for coatings on plastics.
• ISO 3270: Details standard atmosphere conditions for testing.
• ISO 22557: Specifies instruments such as hardness pens used in scratch tests.
• IEC 60068-2-70: Offers guidance on test fabrics and procedures, relevant for abrasion testing with hand abrasion devices.

Practical Value

Adopting ISO 22785-4 ensures rigorous, repeatable abrasion and scratch resistance testing for coated plastic products. It supports quality assurance programs, product development, and compliance with international best practices, helping companies deliver robust, long-lasting products to demanding markets. By following this standard, stakeholders can effectively evaluate, compare, and enhance the surface durability of coated plastics and composites.

International
Standard
ISO 22785-4
First edition
Paints and varnishes — Coatings on
2026-08
plastics and composites —
Part 4:
Abrasion and scratch testing
Peintures et vernis — Revêtements sur plastiques et
composites —
Partie 4: Essais d'abrasion et de rayure
Reference number
© ISO 2026
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 Sample composition and preparation . 2
4.1 Samples .2
4.2 Influence of substrate.2
4.3 Surface condition .2
4.4 Conditioning.2
4.5 Ageing .2
5 Overview of test methods . 3
5.1 Linear abrasion method — linear abrasion tester .3
5.1.1 General .3
5.1.2 Test environment .3
5.1.3 General technical characteristics .3
5.2 Hand abrasion tester .4
5.2.1 General .4
5.2.2 General technical characteristics .4
5.2.3 Particularities .5
5.2.4 Possible sources of error .5
5.3 Scratch tests .5
5.3.1 Manual scratch tests .5
5.3.2 Automatic scratch tests .7
5.4 Rotating abrasion method .8
5.4.1 Taber test.8
5.4.2 Wash scratch resistance .9
5.4.3 Martindale test.10
6 Methods for the evaluation after testing .11
6.1 General .11
6.2 Visual methods .11
6.3 Colour measurement .11
6.4 Gloss measurement .11
6.5 Haze measurement . 12
6.6 Gravimetric methods . 12
Bibliography .13

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,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
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.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9,
General test methods for paints and varnishes.
A list of all parts in the ISO 22785 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
The ISO 22785 series explains the characteristics of plastics and the differences between plastics substrates
and metallic substrates.
v
International Standard ISO 22785-4:2026(en)
Paints and varnishes — Coatings on plastics and
composites —
Part 4:
Abrasion and scratch testing
1 Scope
This document specifies the abrasion and scratch tests of coatings on plastics, plastics composites, and
similar substrates, hereinafter collectively referred to as plastics.
This document shows the potential effect of plastics on the behaviour of the coating during abrasion and
scratch testing.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 4618, Paints and varnishes — Vocabulary
ISO 22785-1, Paints and varnishes — Coatings on plastics and composites — Part 1: General introduction
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618, ISO 22785-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
abrasion resistance
resistance of solid surfaces to mechanical stress, in particular friction
Note 1 to entry: The abrasion resistance is determined by the surface characteristics of the substances involved, such
as roughness and hardness.
3.2
abrasion test
test method which serves for the determination of the abrasion resistance (3.1)
Note 1 to entry: Abrasion can be tested together with various stresses, e.g. media. The stress is normally applied
in parallel and can be applied in different ways. The evaluation is specified respectively, since there are different
evaluation methods (optical change of colour, gloss, transmission/haze, loss of mass).

3.3
surface condition
totality of surface characteristics such as grain, gloss, and roughness
Note 1 to entry: The surface condition has a great influence on the abrasion behaviour.
4 Sample composition and preparation
4.1 Samples
Coatings on specimen plates as specified in ISO 1514 as well as coatings on components are tested. Defects
and damage of all kinds in the substrate affect the appearance and characteristics. The surface shall be
free of any substances that can impair the adhesion of the coating. Likewise, the surface shall be free from
substances sweating out or migrating to the surface over a longer period, potentially due to exposure to
moisture or temperature.
The coating system and the substrate are selected together with the pre-treatment and coating methods so
that a homogeneous coating is achieved. The coating thickness is documented according to the optical or
coating requirement.
Components and samples which are not flat are selected to avoid bending during the test.
4.2 Influence of substrate
The elasticity of the plastics substrate has an influence on the abrasion and scratch resistance of the coating
under test. Typically, the scratch resistance of the coating decreases as the elasticity of the substrate
increases.
4.3 Surface condition
For most abrasion tests, samples with a flat uniform surface are used. Depending on the surface condition or
type of plastic, only certain tests are reasonable.
For retests, the same surface condition of the samples is considered.
4.4 Conditioning
Conditioning serves to increase the repeatability and reproducibility of test results.
The values and times to be selected depend on the material to be tested.
Since the characteristics of plastics substrates strongly depend on humidity and conditioning that usually
takes longer than for metals, a longer conditioning time is normally used for plastics substrates.
Unless otherwise specified, the samples are conditioned for 16 h in the standard climate specified in
ISO 3270.
4.5 Ageing
For some tests and materials, it can be reasonable to use special atmospheres for upstream ageing or drying.
This is shall be documented in the test report.

5 Overview of test methods
5.1 Linear abrasion method — linear abrasion tester
5.1.1 General
By means of a linear abrasion tester as specified in ISO 21546 (see Figure 1), a specified load is applied with
a parallel movement. Testers which can perform a linear back and forth movement (double stroke) with a
suitable friction partner are suitable for the determination of the abrasion resistance. Often the name of
the historically used tester “crockmeter” is used colloquially as the name (“crockmeter test”) for the tests.
There are a variety of testers which are used and reproduce the required conditions.
Key
1 crank mechanism (crank handle)
2 abrasion tool
3 test specimen
a
Direction of stroke motion.
Figure 1 — Crockmeter (example with manual crank mechanism)
5.1.2 Test environment
Carry out the test at a temperature of (23 ± 2) °C. Measure the relative humidity during the test and record
in the test report. In case of high relative humidity, be careful that no condensation water forms on the test
specimen due to falling below the dew point.
Carry out the test as quick as possible, however, not later than 30 min after the conditioning phase.
5.1.3 General technical characteristics
The following adjustable parameters shall be agreed between the interested parties:
— stress (adjustable depending on the device, historically 9 N, additional 1 N to 40 N possible);
— friction path (historically 104 mm, many devices freely adjustable);
— total number of double strokes;
— number of double strokes per time unit;
— friction partner, e.g. cotton fabric, felt, metal, abrasive paper;
— rubbing finger, e.g. rubbing finger A: 16 mm plastic, rubbing finger C: holder for abrasive paper;
— media (dry, wet, cleaning agent, etc.).
Interim assessments are recommended according to internal guidelines.

5.2 Hand abrasion tester
5.2.1 General
These testers simulate hand abrasion by a combination of mechanical and chemical load on the surface.
During this process, a silicone stamp is used to replicate the pliability of the human fingers while the fabric
simulates the roughness and greasiness of the skin. Depending on the requirements, additional media are
used, such as hand sweat and hand cream.
A stamp hits the surface to be tested at a 45° angle (see Figure 2) and runs over it. The supplementary
media, if appropriate, can be applied eit
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