SIST ISO 2846-1:2018

SLOVENSKI STANDARD
SIST ISO 2846-1:2018
01-februar-2018
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SIST ISO 2846-1:2008
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Graphic technology - Colour and transparency of printing ink sets for four-colour printing
- Part 1: Sheet-fed and heat-set web offset lithographic printing
Technologie graphique - Couleur et transparence des gammes d'encre d'impression en
quadrichromie - Partie 1: Impression lithographique offset sur feuilles et à chaud
Ta slovenski standard je istoveten z: ISO 2846-1:2017
ICS:
37.100.01 *UDILþQDWHKQRORJLMDQD Graphic technology in
VSORãQR general
87.080 Barvila. Tiskarske barve Inks. Printing inks
SIST ISO 2846-1:2018 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 2846-1:2018

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SIST ISO 2846-1:2018
INTERNATIONAL ISO
STANDARD 2846-1
Third edition
2017-08
Graphic technology — Colour and
transparency of printing ink sets for
four-colour printing —
Part 1:
Sheet-fed and heat-set web offset
lithographic printing
Technologie graphique — Couleur et transparence des gammes
d’encre d’impression en quadrichromie —
Partie 1: Impression lithographique offset sur feuilles et à bobines
Reference number
ISO 2846-1:2017(E)
©
ISO 2017

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SIST ISO 2846-1:2018
ISO 2846-1:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
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CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

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SIST ISO 2846-1:2018
ISO 2846-1:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test method . 2
4.1 Procedure . 2
4.2 Test print preparation . 3
4.2.1 Prints for colorimetric evaluation. 3
4.2.2 Prints for transparency evaluation . 3
4.2.3 Drying of test prints . 3
4.3 Colour measurement procedures . 3
5 Requirements for colour, transparency and ink film thickness range .4
5.1 General . 4
5.2 Colorimetric values . 4
5.3 Transparency characteristics . 4
5.4 Ink film thickness . 5
Annex A (normative) Reference substrate . 6
Annex B (informative) Extended explanation of the test procedures, including examples .8
Annex C (informative) Spectral data .12
Annex D (informative) Tristimulus values for 8°:di geometry and illuminant D65 .15
Bibliography .17
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SIST ISO 2846-1:2018
ISO 2846-1:2017(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 on 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 the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
This third edition cancels and replaces the second edition (ISO 2846-1:2006), which has been technically
revised.
The main change compared to the previous edition is as follows:
— Annex A has been revised in order to replace the reference substrate and references to other ISO
standards have been updated.
A list of all parts in the ISO 2846 series can be found on the ISO website.
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SIST ISO 2846-1:2018
ISO 2846-1:2017(E)

Introduction
This document defines the colour and transparency of lithographic printing inks. Different sets of inks
(both for proof and production printing) conforming to this document will produce a similar colour
when printed on the same substrate at the appropriate film thickness. This enables colour separations
for offset-lithographic printing to be based on known colour references and simplifies the task of
consistently printing the same images in multiple printing sites.
It should be noted that the colorimetric characteristics specified can only be obtained when the inks
are printed on the reference substrate. However, the similarity of two inks on a reference substrate
generally ensures similarity on another substrate, and it is this similarity that has enabled the
[1]
development of industry specifications or standards such as ISO 12647-2 , which specifies the colour
of these inks on other substrates.
The APCO II/II reference substrate, used for many years, is no longer available and has been replaced by
a new developed reference substrate, C2846, with properties which are for the purpose of this document
similar to the old substrate. Where the new substrate is used for other purposes than specified in this
document, new references may have to be determined.
The colour specified in the previous edition of this document was based on extensive measurements of
commercial ink sets made in Europe, Japan and the USA. A working group of ISO/TC 130 process control
and material experts examined data sets from various countries at the time that edition was prepared
and found that a single set of colour coordinates could adequately represent all three proposals within
reasonable tolerances. In addition, they found that the transparency of various inks could also be
adequately represented by a new method of evaluation. A review undertaken prior to the revision
of this edition suggested that there had been little change in the colour and transparency of the inks
commercially available and that the characteristics specified in this document could be reconfirmed.
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SIST ISO 2846-1:2018

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SIST ISO 2846-1:2018
INTERNATIONAL STANDARD ISO 2846-1:2017(E)
Graphic technology — Colour and transparency of printing
ink sets for four-colour printing —
Part 1:
Sheet-fed and heat-set web offset lithographic printing
1 Scope
This document specifies the colour and transparency characteristics that are to be met by each ink
in a process colour ink set intended for proof and production printing using offset lithography. The
specified printing conditions (which use a laboratory printability tester), the defined substrate and a
method for testing to ensure conformance are also defined. Characteristics are specified for inks used
for sheet-fed, heat-set web and radiation-curing processes.
This document does not apply to fluorescent inks and it does not specify pigments (or spectral
characteristics — except informatively) in order not to preclude developments which may enable
different pigment combinations to be used advantageously while still achieving the colorimetric
requirements specified in this document.
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 535, Paper and board — Determination of water absorptiveness — Cobb method
ISO 536, Paper and board — Determination of grammage
ISO 2144, Paper, board and pulps — Determination of residue (ash) on ignition at 900 °C
ISO 2834-1, Graphic technology — Laboratory preparation of test prints — Part 1: Paste inks
ISO 6588-1, Paper, board and pulps — Determination of pH of aqueous extracts — Part 1: Cold extraction
ISO 8254-1, Paper and board — Measurement of specular gloss — Part 1: 75 degree gloss with a converging
beam, TAPPI method
ISO 8791-4, Paper and board — Determination of roughness/smoothness (air leak methods) — Part 4:
Print-surf method
ISO 13655:2009, Graphic technology — Spectral measurement and colorimetric computation for graphic
arts images
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:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
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ISO 2846-1:2017(E)

3.1
0°:45° or 45°:0°
measurement geometry of a spectrophotometer in conformance with ISO 13655 geometry 0°:45° or 45°:0°
3.2
8°:di or di:8°
hemispherical diffuse geometry, specular component included, with either 8° incidence (influx) (8°:di)
or 8° exitance (efflux) (di:8°)
Note 1 to entry: The measurement geometry of a spectrophotometer not in conformance with ISO 13655.
3.3
ink
printing ink
composite material containing colorants, functional components, vehicle and additives
Note 1 to entry: In most cases, applied as a fluid to a substrate by a printing process and setting or drying by
either physical (evaporation) and/or chemical (polymerizations, e.g. oxidation, radiation induced, or other)
processes to form an image for decorative, informative or technical purposes.
3.4
standard ink
process ink
ink (3.3) intended for four-colour printing which, when printed on the reference substrate and within the
applicable range of ink film thicknesses, complies to the colorimetric and transparency specifications
of this document
3.5
transparency
ability of an ink (3.3) film to transmit light
Note 1 to entry: It is generally expressed as some measure of the unwanted scattering.
3.6
transparency value
T
reciprocal of the slope of the regression line between ink (3.3) film thickness and colour difference for
overprints of chromatic inks over black substrate
4 Test method
4.1 Procedure
Colorimetric conformance shall be verified by printing each ink on the reference substrate, described
in Annex A, at a range of ink film thicknesses. The colours of the resultant test prints shall be measured
and the colour difference determined between the sample and the pertinent value given in Table 1. If at
least one of these samples has a smaller colour difference than that specified in 5.2, the ink conforms
colorimetrically to this document.
NOTE It is often more convenient to determine the colorimetric conformance of an ink graphically. This
is achieved by calculating the colour difference (ΔE* ) from the values in Table 1 for each of the prints made
ab
and plotting this against the ink film thickness. The ink conforms if the resultant curve shows a pronounced
minimum which is below the ΔE* value specified in Table 1. (See Annex B for further information.)
ab
Transparency value, T, shall be determined by printing each of the chromatic process inks on to a black
substrate meeting the requirements of 4.2.2, at a range of ink film thicknesses. The colour difference,
ΔE* , is determined for each sample between the overprinted and unprinted black substrate. The
ab
gradient of the linear regression of ink film thickness against colour difference shall be determined.
An ink conforms to the transparency requirements of this document if the reciprocal of the gradient is
negative, or greater than the value specified. (See Annex B for further information.)
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The gradient of the regression equation may be determined directly from the data obtained. However,
it is recommended that it be obtained from a graphical plot of the values of ΔE* against ink film
ab
thickness. Such a plot enables any unexpected characteristics of the data to be easily visualized. (See
Annex B for further information.)
If one or more printed samples of each ink conform to the colorimetric values within the tolerances
specified at an ink film within the thickness range specified, and the ink also meets the transparency
criteria, that ink can be said to comply to this document.
4.2 Test print preparation
4.2.1 Prints for colorimetric evaluation
For each of the inks to be evaluated, several test prints shall be made, each produced at a different ink
film thickness, according to the conditions specified in ISO 2834-1.
They shall be made on the reference substrate specified in Annex A. The range of ink film thicknesses
produced shall encompass the range specified for the process for which the ink is intended. (See 5.4.)
4.2.2 Prints for transparency evaluation
The test prints for transparency evaluation shall be produced by printing the inks to be tested on a black
substrate such that a minimum of four samples is achieved, each with a different ink film thickness. The
printing shall be undertaken as described in ISO 2834-1. The range of ink film thicknesses achieved
shall not exceed that defined in 5.4.
NOTE Test prints with ink film thicknesses below 0,7 µm can cause errors in the transparency evaluation.
The black substrate shall have a lightness, L*, less than 6 when determined in accordance with
ISO 13655:2009, M0, M1 or M2 (with the exception that a white backing shall be used when measuring
the print; see 4.3). The black substrate shall have a gloss of (80 ± 5) GU measured according to
ISO 8254-1.
Although in principle, it is possible for the user to produce themselves the black substrate by printing,
it is difficult to ensure that the lightness is sufficiently low without adversely affecting the gloss and
printing properties of the substrate. It is usually preferable to use a black substrate or a substrate
pre-printed commercially. However, if it is necessary to print the black, the recommendations given in
1)
Annex B should be followed. Appropriate substrates are the contrast card or the contrast strip .
4.2.3 Drying of test prints
Prior to colour measurement, all samples shall be thoroughly dried. Inks formulated for oxidation
drying shall be left for at least 24 h, those formulated for radiation curing shall be dried with an
appropriate radiation source within the appropriate time and energy and heat-set inks shall be heat
dried with appropriate drying equipment.
NOTE Be aware that the appropriate time for radiation curing inks can be down to parts of a second only.
4.3 Colour measurement procedures
Test prints shall be measured in accordance with ISO 13655 using white backing. Measurement
condition M1 should be used. M0 or M2 may be used and should not give difference in results.
Conforming to ISO 13655:2009, M1 means that samples shall be measured spectrally, with a 0°:45° or
45°:0° geometry instrument, and for calculation of CIELAB colour values, the CIE 1931 (2°) standard
1) Comparison test strips CT2846 with contrast band from IGT Testing Systems (www .igt .nl), NL-1316 BX Almere,
The Netherlands. These products are examples of a suitable product available commercially. This information is
given for the convenience of users of this document and does not constitute an endorsement by ISO of these products.
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ISO 2846-1:2017(E)

colorimetric observer data are used together with CIE standard illuminant D50 including calibrated UV
level; see Reference [3]. Where spectral data are obtained at wavelength intervals greater than 5 nm,
the weighting functions for the standard colorimetric observer specified in ISO 13655 shall be used.
For calculating the colour difference from the reference values, the CIE 1976 colour difference, ΔE* ,
ab
shall be used.
NOTE For the comparison of measurements, it is useful to record the following detai
...