Abstract

Procedure for comparing the colour of a coloured pigment with that of an agreed sample. The procedures described in this document are acceptable but the method using an automatic muller is the reference method. The binder is not specified. It shall be agreed between the interested parties. If no binder is agreed, linseed oil, complying with the specification in ISO 150, should be used. - Replaces ISO/R 787/1:1968.

Status
Not Published
Publication Date
24-Jan-2027
ICS
87.060.10 - Pigments and extenders
Technical Committee
CEN/TC 298 - Pigments and extenders
Drafting Committee
CEN/TC 298 - Pigments and extenders
Current Stage
5020 - Submission to Vote - Formal Approval
Start Date
27-Aug-2026
Completion Date
27-Aug-2026
Ref Project
kSIST FprEN ISO 787-1:2026 - General methods of test for pigments and extenders - Part 1: Comparison of colour of pigments (ISO/FDIS 787-1:2026)

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FprEN ISO 787-1 is a standard in the ISO 787 series for pigments and extenders. It specifies how to compare the colour of a coloured pigment with an agreed sample, using either an automatic muller reference method or a hand muller or palette knife procedure.

The standard is used when two pigment preparations need to be checked for colour match under a repeatable laboratory procedure. In practice, it helps suppliers, buyers, and test laboratories prepare comparable dispersions and judge whether the colours are equal or different.

What does FprEN ISO 787-1 specify?

FprEN ISO 787-1 specifies a general test method for colour comparison of pigments and the way the test result is reported. The document focuses on preparing pigment dispersions, comparing them against an agreed sample, and recording the outcome in a consistent way.

The document is organized into scope, normative references, terms and definitions, apparatus and materials, sampling, sample generation, colour comparison, and test report. Clause 6 gives two preparation procedures, and Clause 7 gives both visual and colorimetric comparison options.

What are the key requirements of FprEN ISO 787-1?

Sample preparation and reference method

FprEN ISO 787-1 allows two procedures in Clause 6, but the automatic muller procedure is the reference method. This matters because users who need the closest traceable comparison should treat the automatic muller route as the primary one.

For the automatic muller, the test portion must be weighed to the nearest 1 mg, mixed with binder to a suitable paste, and ground in stages of 50 revolutions. The same force and number of stages must be used for the test pigment and the agreed sample. In practice, this means both specimens have to be prepared under matched conditions so the colour difference comes from the pigment, not from the milling history.

The hand muller or palette knife procedure uses a test portion between 0.1 g and 1.0 g, depending on oil absorption value. The mixture is rubbed out in repeated cycles, then brought to a homogeneous paste before comparison. This gives a practical alternative when the automatic muller is not available.

Binder, apparatus and sampling

FprEN ISO 787-1 requires the binder to be agreed between the interested parties. If no binder is agreed, refined linseed oil complying with ISO 150 is used. That makes the medium part of the agreed test conditions, which is important because the binder can affect colour development.

Clause 4 also specifies the basic apparatus: palette knife, substrate, burette, muller, and, when needed, a glass or marble plate. If a glass panel is used as the substrate, it must be clear and colourless. Clause 5 requires sampling in accordance with ISO 15528, so the tested material should represent the batch.

Colour comparison

Clause 7 compares the two prepared pastes as opaque strips at least 25 mm wide with touching edges and at least 40 mm long. Visual comparison is done in diffuse daylight, or through the glass by agreement, following ISO 3668. Artificial daylight is preferred for reproducible results. In practice, this is the step where the colour match is judged and the result is either equal to or different from the agreed sample.

By agreement, a colorimeter may also be used. In that case, the procedure follows ISO 18314-1, with colour differences calculated using ISO/CIE 11664-4, and total colour difference calculated using ISO/CIE 11664-6 or ISO 18314-5. This gives a measured result instead of, or alongside, the visual judgment.

Test report

Clause 8 requires the report to identify the pigment, the binder used, the procedure used, the comparison method, and the final result. It also requires any deviations and unusual observations to be recorded. This helps quality control, dispute resolution, and repeat testing.

What terms does FprEN ISO 787-1 define?

  • Binder - The medium mixed with the pigment to make the paste for comparison; if the parties do not agree another binder, refined linseed oil is used.
  • Automatic muller - A grinding device with opposed plates used to prepare pigment dispersion under controlled force and revolutions.
  • Hand muller - A smaller manual grinding tool used with a plate to prepare the pigment paste.
  • Substrate - The surface on which the two prepared pastes are spread for colour comparison.
  • Agreed sample - The reference pigment sample against which the test pigment is compared.
  • Colorimeter - An instrument used, by agreement, to measure colour differences instead of relying only on visual assessment.

Who uses FprEN ISO 787-1?

FprEN ISO 787-1 is used by pigment manufacturers, paint and coating laboratories, quality control teams, and buyers who need to compare pigment colour against a reference sample. It is also relevant to testing laboratories that prepare dispersions and report whether two pigment materials match in colour.

What changed in FprEN ISO 787-1 from the previous edition?

FprEN ISO 787-1 is a technically revised second edition that cancels and replaces ISO 787-1:1982. The stated changes are:

  • Clause 3 on terms and definitions was added.
  • Clause 7 adds the colorimeter method for colour measurement and colour comparison.
  • The normative references were updated.

The scope also notes replacement of ISO/R 787/1:1968.

Which standards are used with FprEN ISO 787-1?

  • ISO 150 - Gives the specification for refined linseed oil when no binder is agreed.
  • ISO 3668 - Provides the procedure for visual comparison of colour.
  • ISO 15528 - Provides the sampling method for paints, varnishes, and raw materials.
  • ISO 18314-1 - Gives the practical procedure for colorimetric measurement.
  • ISO 18314-5 - Gives the procedure for colorimetric determination of colour differences in equidistant colour spaces.
  • ISO 18451-1 - Supplies the general pigment and extender terminology used in Clause 3.
  • ISO/CIE 11664-4 - Defines the CIE 1976 Lab* colour space used for colour-difference calculation.
  • ISO/CIE 11664-6 - Provides the CIEDE2000 colour-difference formula.

What does the FprEN ISO 787-1 document contain?

FprEN ISO 787-1 contains a test method, apparatus list, sampling instruction, two sample-preparation procedures, a colour-comparison procedure, and a test report checklist. Clause 6 describes how to prepare the pigment dispersion with an automatic muller or with a hand muller or palette knife.

Clause 7 describes how to spread the pastes for visual checking and how to use a colorimeter by agreement. Clause 8 lists the minimum reporting items, including the binder, the procedure used, the comparison result, and any anomalies.

Relations

Consolidated By
ISO/FDIS 787-1 - General methods of test for pigments and extenders — Part 1: Comparison of colour of pigments
Effective Date
12-Feb-2026
Revises
EN ISO 787-1:2017 - General methods of test for pigments and extenders - Part 1: Comparison of colour of pigments (ISO 787-1:1982)
Effective Date
30-Oct-2024

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Frequently Asked Questions

FprEN ISO 787-1 is a draft published by the European Committee for Standardization (CEN). Its full title is "General methods of test for pigments and extenders - Part 1: Comparison of colour of pigments (ISO/FDIS 787-1:2026)". This standard covers: Procedure for comparing the colour of a coloured pigment with that of an agreed sample. The procedures described in this document are acceptable but the method using an automatic muller is the reference method. The binder is not specified. It shall be agreed between the interested parties. If no binder is agreed, linseed oil, complying with the specification in ISO 150, should be used. - Replaces ISO/R 787/1:1968.

Procedure for comparing the colour of a coloured pigment with that of an agreed sample. The procedures described in this document are acceptable but the method using an automatic muller is the reference method. The binder is not specified. It shall be agreed between the interested parties. If no binder is agreed, linseed oil, complying with the specification in ISO 150, should be used. - Replaces ISO/R 787/1:1968.

FprEN ISO 787-1 is classified under the following ICS (International Classification for Standards) categories: 87.060.10 - Pigments and extenders. The ICS classification helps identify the subject area and facilitates finding related standards.

FprEN ISO 787-1 has the following relationships with other standards: It is inter standard links to ISO/FDIS 787-1, EN ISO 787-1:2017. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.

FprEN ISO 787-1 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.

Standards Content (Sample)


SLOVENSKI STANDARD
oSIST prEN ISO 787-1:2026
01-maj-2026
Splošne preskusne metode za pigmente in polnila - 1. del: Primerjava barve
pigmentov (ISO/DIS 787-1:2026)
General methods of test for pigments and extenders - Part 1: Comparison of colour of
pigments (ISO/DIS 787-1:2026)
Allgemeine Prüfverfahren für Pigmente und Füllstoffe - Teil 1: Farbvergleich von
Pigmenten (ISO/DIS 787-1:2026)
Méthodes générales d'essai des pigments et matières de charge - Partie 1:
Comparaison de la couleur des pigments (ISO/DIS 787-1:2026)
Ta slovenski standard je istoveten z: prEN ISO 787-1
ICS:
87.060.10 Pigmenti in polnila Pigments and extenders
oSIST prEN ISO 787-1:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN ISO 787-1:2026
oSIST prEN ISO 787-1:2026
DRAFT
International
Standard
ISO/DIS 787-1
ISO/TC 256
General methods of test for
Secretariat: DIN
pigments and extenders —
Voting begins on:
Part 1: 2026-03-24
Comparison of colour of pigments
Voting terminates on:
2026-06-16
Méthodes générales d'essai des pigments et matières de charge —
Partie 1: Comparaison de la couleur des pigments
ICS: 87.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 787-1:2026(en)
oSIST prEN ISO 787-1:2026
DRAFT
ISO/DIS 787-1:2026(en)
International
Standard
ISO/DIS 787-1
ISO/TC 256
General methods of test for
Secretariat: DIN
pigments and extenders —
Voting begins on:
Part 1:
2026-03-24
Comparison of colour of pigments
Voting terminates on:
2026-06-16
Méthodes générales d'essai des pigments et matières de charge —
Partie 1: Comparaison de la couleur des pigments
ICS: 87.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
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NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 787-1:2026(en)
ii
oSIST prEN ISO 787-1:2026
ISO/DIS 787-1:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus and materials . 1
5 Sampling . 2
6 Procedure for sample generation . 2
6.1 Procedure using an automatic muller.2
6.1.1 Test portion .2
6.1.2 Preparation of pigment dispersion .2
6.2 Procedure using a hand muller or palette knife .3
6.2.1 Test portion .3
6.2.2 Preparation of pigment dispersion .3
7 Colour comparison . 3
8 Test report . 3

iii
oSIST prEN ISO 787-1:2026
ISO/DIS 787-1:2026(en)
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
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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 documents should be noted. This document was drafted in accordance with the editorial rules of the
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This document was prepared by Technical Committee ISO/TC 256, Pigments, dyestuffs and extenders, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 298,
Pigments and extenders, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
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