SIST EN ISO 12625-7:2021

Tissue paper and tissue products - Part 7: Determination of optical properties - Measurement of brightness and colour with D65/10° (outdoor daylight) (ISO 12625-7:2021)

This document specifies testing procedures for the instrumental determination of brightness and colour of tissue paper and tissue products viewed under outdoor daylight conditions. It also gives specific instructions for the preparation of test pieces (single-ply, multi-ply products) and for the optical measurements of products, where special precautions can be necessary.
NOTE       The properties called ISO brightness and colour with C/2° (indoor daylight) are measured with an instrument adjusted to a much lower UV content than that specified in this document. The measurements of ISO brightness and colour with C/2° (indoor daylight) are described in ISO 12625-15.

Tissue-Papier und Tissue-Produkte - Teil 7: Bestimmung der optischen Eigenschaften - Brightness- und Farbmessung mit Lichtart D65/10° (Außentageslicht) (ISO 12625-7:2021)

Dieses Dokument legt Prüfverfahren für die instrumentelle Bestimmung von Brightness und Farbe für Tissue-Papier und Tissue-Produkte unter Tageslichtbedingungen fest. Es werden auch genaue Anweisungen für die Vorbereitung von Messproben (einlagige, mehrlagige Produkte) und für die optischen Messungen von Produkten gegeben, bei denen besondere Vorsichtsmaßnahmen notwendig sein können.
ANMERKUNG   Die als ISO Brightness und  Farbe mit Lichtart C/2° (Tageslichtbedingungen in Innenräumen) bezeichneten Eigenschaften werden mit einem Gerät gemessen, das auf einen viel geringeren UV-Anteil angepasst ist als in diesem Dokument festgelegt wird. Die Messungen von ISO Brightness und  Farbe mit Lichtart C/2° (Tageslichtbedingungen in Innenräumen) werden in ISO 12625 15 beschrieben.

Papier tissue et produits tissue - Partie 7: Détermination des propriétés optiques - Mesurage du degré de blancheur et de la couleur en D65/10° (lumière du jour extérieure) (ISO 12625-7:2021)

Le présent document spécifie des modes opératoires d’essai pour la détermination instrumentale du degré de blancheur et de la couleur des papiers tissue et des produits tissue observés dans les conditions de lumière du jour extérieure. Il donne également des instructions spécifiques pour la préparation des éprouvettes (produits à pli unique, produits multiplis) ainsi que pour les mesures optiques des produits, lorsque des précautions particulières peuvent se révéler nécessaires.
NOTE            Les propriétés appelées degré de blancheur ISO et couleur C/2° (lumière du jour à l’intérieur) sont mesurées avec un appareil réglé à une teneur en UV très inférieure à celle spécifiée dans le présent document. Les mesurages du degré de blancheur ISO et de la couleur en C/2° (lumière du jour à l’intérieur) sont décrits dans l’ISO 12625-15.

Tissue papir in izdelki iz tissue papirja - 7. del: Določevanje optičnih lastnosti - Merjenje beline in barve z D65/10° (zunanja dnevna svetloba) (ISO 12625-7:2021)

General Information

• Status: Published
• Public Enquiry End Date: 19-Nov-2020
• Publication Date: 11-Oct-2021
• ICS: 17.180.20 - Colours and measurement of light
• ICS: 85.080.20 - Tissue paper
• Technical Committee: VPK - Pulp, paper, board and products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 29-Sep-2021
• Due Date: 04-Dec-2021
• Completion Date: 12-Oct-2021
• Ref Project: EN ISO 12625-7:2021 - Tissue paper and tissue products - Part 7: Determination of optical properties - Measurement of brightness and colour with D65/10° (outdoor daylight) (ISO 12625-7:2021)

Relations

• Replaces: SIST EN ISO 12625-7:2014 - Tissue paper and tissue products - Part 7: Determination of optical properties - Measurement of brightness and colour with D65/10° (outdoor daylight) (ISO 12625-7:2014)
• Effective Date: 01-Nov-2021

Overview

EN ISO 12625-7:2021 - "Tissue paper and tissue products - Part 7: Determination of optical properties - Measurement of brightness and colour with D65/10° (outdoor daylight)" is a CEN-endorsed ISO test method for instrumental measurement of brightness and colour of tissue under outdoor daylight conditions (D65/10°). The standard defines how to prepare single-ply and multi-ply test pieces, set up instruments, and record results so that optical properties of tissue products are measured reproducibly and traceably.

Key topics and requirements

• Scope: Procedures for instrumental determination of brightness and colour of tissue paper/products under D65/10° (outdoor daylight). Notes distinguish these from C/2° (indoor daylight) measurements in ISO 12625-15.
• Terms and definitions: Includes key optical terms such as diffuse radiance factor and intrinsic diffuse radiance factor that underpin measurement interpretation.
• Apparatus and calibration: Requires instruments designed and calibrated in line with referenced standards (for example ISO 2469, ISO 11475) to ensure accurate D65/10° measurement and traceability.
• Sampling and conditioning: Refers to ISO 186 and ISO 187 for representative sampling and standard atmosphere conditioning before testing.
• Preparation of test pieces: Specific instructions for single-ply and multi-ply products, with precautions where texture or structure affects optical readings.
• Procedure and calculation: Stepwise measurement of D65 brightness and colour (including CIE-based colourimetric reporting) and calculation of single, mean and dispersion values. Annex on precision gives expected measurement repeatability/reproducibility.
• Reporting: Minimum information to include in a test report so results are auditable and comparable.

Practical applications and users

This standard is essential for:

• Tissue manufacturers monitoring product appearance and consistency (brightness, colour).
• Quality control and laboratory staff performing routine optical testing and acceptance testing.
• Product development teams comparing formulations, bleaching or whitening strategies.
• Suppliers and purchasers specifying optical properties in contracts and procurement.
• Test laboratories and certification bodies seeking standardized D65/10° measurement methods for accreditation and reporting.

Benefits include consistent color and brightness data, improved product matching across batches, and defensible specifications for marketing and compliance.

Related standards

• ISO 2469 - Measurement of diffuse radiance factor (diffuse reflectance)
• ISO 11475 - Determination of CIE whiteness, D65/10°
• ISO 12625-15 - Brightness and colour with C/2° (indoor daylight)
• ISO 12625-16 - (other optical methods for tissue)
• ISO 186, ISO 187, ISO 4094, ISO/CIE 11664-4 - sampling, conditioning, calibration and colourimetry references

Keywords: EN ISO 12625-7:2021, tissue paper, optical properties, D65/10°, brightness measurement, colour measurement, tissue products, ISO standard.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST EN ISO 12625-7:2014
Tissue papir in izdelki iz tissue papirja - 7. del: Določevanje optičnih lastnosti -
Merjenje beline in barve z D65/10° (zunanja dnevna svetloba) (ISO 12625-7:2021)
Tissue paper and tissue products - Part 7: Determination of optical properties -
Measurement of brightness and colour with D65/10° (outdoor daylight) (ISO 12625-
7:2021)
Tissue-Papier und Tissue-Produkte - Teil 7: Bestimmung der optischen Eigenschaften -
Brightness- und Farbmessung mit Lichtart D65/10° (Außentageslicht) (ISO 12625-
7:2021)
Papier tissue et produits tissue - Partie 7: Détermination des propriétés optiques -
Mesurage du degré de blancheur et de la couleur en D65/10° (lumière du jour
extérieure) (ISO 12625-7:2021)
Ta slovenski standard je istoveten z: EN ISO 12625-7:2021
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
85.080.20 Tissue papir Tissue paper
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 12625-7
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2021
EUROPÄISCHE NORM
ICS 85.080.20 Supersedes EN ISO 12625-7:2014
English Version
Tissue paper and tissue products - Part 7: Determination
of optical properties - Measurement of brightness and
colour with D65/10° (outdoor daylight) (ISO 12625-
7:2021)
Papier tissue et produits tissue - Partie 7: Tissue-Papier und Tissue-Produkte - Teil 7:
Détermination des propriétés optiques - Mesurage du Bestimmung der optischen Eigenschaften - Brightness-
degré de blancheur et de la couleur en D65/10° und Farbmessung mit Lichtart D65/10°
(lumière du jour extérieure) (ISO 12625-7:2021) (Außentageslicht) (ISO 12625-7:2021)
This European Standard was approved by CEN on 14 August 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12625-7:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 12625-7:2021) has been prepared by Technical Committee ISO/TC 6 "Paper,
board and pulps" in collaboration with Technical Committee CEN/TC 172 “Pulp, paper and board” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2022, and conflicting national standards shall
be withdrawn at the latest by March 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 12625-7:2014.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN websites.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 12625-7:2021 has been approved by CEN as EN ISO 12625-7:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 12625-7
Third edition
2021-08
Tissue paper and tissue products —
Part 7:
Determination of optical properties —
Measurement of brightness and colour
with D65/10° (outdoor daylight)
Papier tissue et produits tissue —
Partie 7: Détermination des propriétés optiques — Mesurage du
degré de blancheur et de la couleur en D65/10° (lumière du jour
extérieure)
Reference number
ISO 12625-7:2021(E)
©
ISO 2021
ISO 12625-7:2021(E)
© ISO 2021
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 © ISO 2021 – All rights reserved

ISO 12625-7:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 3
6 Calibration . 4
7 Sampling . 5
8 Conditioning . 5
9 Preparation of test pieces . 5
10 Procedure. 5
10.1 General . 5
10.2 Measurement of D65 brightness . 5
10.3 Measurement of colour (D65/10°) . 6
11 Calculation . 6
11.1 D65 brightness . 6
11.2 Colour (D65/10°) . 6
11.2.1 Single value . 6
11.2.2 Mean value . 7
11.2.3 Dispersion of the results . 7
12 Test report . 7
Annex A (informative) Precision . 9
Bibliography .12
ISO 12625-7:2021(E)
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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 6, Paper, board and pulps, Subcommittee
SC 2, Test methods and quality specifications for paper and board, in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 172, Pulp, paper and board, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 12625-7:2014), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— alternative formulae in 11.2.1 have been removed because they were not relevant for tissue paper.
A list of all parts in the ISO 12625 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 © ISO 2021 – All rights reserved

ISO 12625-7:2021(E)
Introduction
Brightness and colour measurement can be performed under various illumination and observation
conditions. This document deals with D65/10° conditions, which refer to an outdoor daylight.
C/2° conditions (indoor daylight) are considered in ISO 12625-15. Although both International
Standards deal with brightness and colour, results obtained are usually different and do not correlate.
Optical measurement is affected by the geometry of the instruments used and by the texture of the
material. The design of the instrument to use according to this document and the routine to adopt for
its calibration are specified in ISO 2469 and ISO 11475.
The optical properties are related to the visual appearance of the material. Therefore, although optical
properties are intrinsic properties of tissue paper, they are not functional properties.
Brightness should not be confused with the optical property called CIE whiteness, which is based on
reflectance data obtained over the full visible spectral range (VIS) in contrast to the measurement of
brightness, which is limited to the blue region of VIS.
Due to its importance for some countries, three different test methods for the determination of optical
properties were developed:
— this document, i.e. ISO 12625-7;
— ISO 12625-15;
— ISO 12625-16.
INTERNATIONAL STANDARD ISO 12625-7:2021(E)
Tissue paper and tissue products —
Part 7:
Determination of optical properties — Measurement of
brightness and colour with D65/10° (outdoor daylight)
1 Scope
This document specifies testing procedures for the instrumental determination of brightness and
colour of tissue paper and tissue products viewed under outdoor daylight conditions. It also gives
specific instructions for the preparation of test pieces (single-ply, multi-ply products) and for the optical
measurements of products, where special precautions can be necessary.
NOTE The properties called ISO brightness and colour with C/2° (indoor daylight) are measured with an
instrument adjusted to a much lower UV content than that specified in this document. The measurements of ISO
brightness and colour with C/2° (indoor daylight) are described in ISO 12625-15.
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 186, Paper and board — Sampling to determine average quality
ISO 187, Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for
monitoring the atmosphere and conditioning of samples
ISO 2469, Paper, board and pulps — Measurement of diffuse radiance factor (diffuse reflectance factor)
ISO 4094, Paper, board and pulps — General requirements for the competence of laboratories authorized
for the issue of optical reference transfer standards of level 3
ISO 11475:2017, Paper and board — Determination of CIE whiteness, D65/10 degrees (outdoor daylight)
ISO/CIE 11664-4, Colorimetry — Part 4: CIE 1976 L*a*b* colour space
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
diffuse radiance factor
R
ratio of the radiation reflected and emitted from a body to that reflected from the perfect reflecting
diffuser under the same conditions of diffuse illumination and normal detection
Note 1 to entry: The ratio is often expressed as a percentage.
ISO 12625-7:2021(E)
[SOURCE: ISO 2469:2014, 3.2]
3.2
intrinsic diffuse radiance factor
R
∞
diffuse radiance factor (3.1) of a layer or pad of material thick enough to be opaque, i.e. such that
increasing the thickness of the pad by doubling the number of sheets results in no change in the
measured radiance factor
Note 1 to entry: The radiance factor of a single non-opaque sheet is dependent on the background and is not a
material property.
Note 2 to entry: The ratio is often expressed as a percentage.
[SOURCE: ISO 2469:2014, 3.3]
3.3
reflectance factor
quotient of the flux reflected in the directions by a given cone with apex at a surface element and the
flux reflected in the same directions by a perfect reflecting diffuser identically irradiated or illuminated
Note 1 to entry: The ratio is often expressed as a percentage.
Note 2 to entry: This term shall be used only when it is known that the test material exhibits no luminescence
(fluorescence).
[SOURCE: CIE S 017 ILV: 2020, 17-24-070]
3.4
D65 brightness
intrinsic diffuse radiance factor (3.2) measured with a reflectometer having the characteristics described
in ISO 2469, equipped with a filter or corresponding function having an effective wavelength of 457 nm
(and a half bandwidth of 44 nm), and adjusted so that the UV content of the irradiation incident upon
the test piece corresponds to that of the CIE standard illuminant D65
Note 1 to entry: The filter function is described more fully by the weighting factors given in ISO 2470-2.
3.5
tristimulus values
X ,Y ,Z
10 10 10
amounts of the reference colour stimuli, in a given trichromatic system, required to match the colour of
the stimulus considered
Note 1 to entry: In ISO 5631-2 the CIE standard illuminant D65 and the CIE 1964 (10°) standard observer are
...