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

ISO 22785-4:2026 is an International Standard from ISO for abrasion and scratch testing of coatings on plastics, plastics composites, and similar substrates. It specifies how to prepare the samples, which test methods can be used, and how to evaluate the coating after testing, with attention to how the plastic substrate can change the coating’s behavior.

What does ISO 22785-4:2026 specify?

ISO 22785-4:2026 specifies abrasion and scratch tests for coatings on plastics, plastics composites, and similar substrates, which the document treats collectively as plastics. It is organized as a practical test-method guide, moving from sample preparation to test methods and then to post-test evaluation.

The document is structured into these main parts:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Sample composition and preparation
• Clause 5 - Overview of test methods
• Clause 6 - Methods for the evaluation after testing
• Bibliography

The introduction states that the ISO 22785 series explains the characteristics of plastics and the differences between plastics substrates and metallic substrates. In practice, that matters because the substrate itself can affect how a coating wears or scratches.

What are the key requirements of ISO 22785-4:2026?

ISO 22785-4:2026 focuses on choosing suitable specimens, controlling the test conditions, and selecting an evaluation method that matches the type of damage being studied. The document is especially useful when the plastic substrate can influence the result, which is often the case in scratch testing.

Sample preparation and conditioning

Clause 4 says coatings may be tested on specimen plates as specified in ISO 1514 and on coated components. The substrate surface should be clean and free from contamination or migrating substances, and the coating system and pre-treatment should be chosen so a uniform coating is achieved.

Clause 4.4 also makes conditioning important: samples are generally conditioned in the standard climate specified in ISO 3270 for 16 h unless otherwise specified. This matters because plastics respond strongly to humidity and conditioning time, so test results become more repeatable when the samples are handled consistently.

Linear abrasion testing

Clause 5.1 describes the linear abrasion method using a linear abrasion tester as specified in ISO 21546. The test uses a controlled load, stroke length, friction partner and medium, and the test environment is controlled at (23 ± 2) °C while relative humidity is recorded.

In practice, this method is used when a straight rubbing action is needed, such as with a crockmeter-style test. The document says the parties involved should agree the main parameters in advance, because those choices strongly affect comparability.

Hand abrasion testing

Clause 5.2 covers hand abrasion testers, which simulate rubbing by fingers and hands using a silicone stamp, fabric and optional media such as sweat, cream or cleaning agents. The adjustable items include test path, fabric type, pressing force, pressing duration and friction speed.

This matters for markings and letterings that may be touched repeatedly in use. The method is useful when the surface sees localized hand-like wear rather than a broad mechanical rubbing action.

Scratch testing

Clause 5.3 separates manual scratch tests from automatic scratch tests. Manual tests use tools such as hardness pens specified in ISO 22557 or gash resistance testers, while automatic tests can be done with devices such as a linear abrasion tester, hand abrasion tester or universal scratch test rig.

The practical difference is control and repeatability. Manual scratch tests can suit production checks and complex shapes, while automatic tests allow controlled loads, speeds and scratch grids for more objective comparison.

Rotating abrasion and related methods

Clause 5.4 covers the Taber test, wash scratch resistance and the Martindale test. These methods use rotating or multi-directional abrasion to assess how the coating holds up under repeated mechanical action.

The Taber test is the most clearly defined of the three for abrasive wear, while wash scratch resistance simulates car-wash brush action and Martindale uses a Lissajous movement. The document notes that Martindale is rarely used for plastics because reproducibility can be difficult.

Post-test evaluation

Clause 6 gives the main ways to assess the result: visual inspection, colour measurement, gloss measurement, haze measurement and gravimetric evaluation. The chosen method depends on the coating and on the type of damage expected.

This is important because abrasion is not always measured by mass loss alone. On coated plastics, appearance changes such as colour shift, gloss loss or haze can be just as important as physical wear.

What terms does ISO 22785-4:2026 define?

ISO 22785-4:2026 defines three core terms in Clause 3 and uses a few practical testing terms throughout the document.

• Abrasion resistance - the ability of a solid surface to resist mechanical stress, especially friction.
• Abrasion test - a test method used to determine abrasion resistance.
• Surface condition - the overall surface character, including grain, gloss and roughness, which strongly affects abrasion behavior.
• Conditioning - controlled pre-test storage of samples so that results are more repeatable and reproducible.
• Scratch test - a practical test used in the document for assessing resistance to scratch loads.

Who uses ISO 22785-4:2026?

ISO 22785-4:2026 is used by testing laboratories, coating manufacturers, plastics processors, automotive suppliers and quality teams that need to compare abrasion or scratch resistance on coated plastic parts. It is also useful for buyers and specifiers who must agree test conditions, evaluate appearance changes, or compare materials and surface treatments.

Which standards are used with ISO 22785-4:2026?

ISO 22785-4:2026 cites ISO 4618 for coating vocabulary and ISO 22785-1 for the general introduction to coatings on plastics and composites. It also relies on several supporting standards for conditioning, apparatus and evaluation, including ISO 3270, ISO 21546, ISO 22557, ISO 20566, ISO 2813, ISO 13076, ISO 18314-1 and ISO 13803.

What does the ISO 22785-4:2026 document contain?

ISO 22785-4:2026 contains sample-preparation guidance, overviews of several abrasion and scratch methods, and the main post-test evaluation options. It includes schematic figures for the linear abrasion tester, the hand abrasion tester, the hardness pen, the Taber principle and the Martindale movement path.

The document also explains method-specific parameters such as load, stroke, speed, test distance, fabric, friction partner and media. For rotating and wash-scratch methods, it describes how the test setup, specimen shape and reference plates affect repeatability and wear monitoring.

The evaluation section gives the practical routes for judging damage by eye or by measurement. That makes the standard useful both for routine quality checks and for comparing test results across different laboratories.

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
...