SIST-TS ISO TS 15311-2:2020
Graphic technology - Print quality requirements for printed matter - Part 2: Commercial print applications utilizing digital printing technologies
Graphic technology - Print quality requirements for printed matter - Part 2: Commercial print applications utilizing digital printing technologies
ISO/TS 15311-2 gives guidance to print buyers and other users of print for assessing printed products on isotropic substrates that are typically held at a viewing distance of 30 to 50 cm. It specifies the proper application of required, recommended and optional metrics, measurement methods and, where appropriate, reporting requirements in the general commercial market. Although this document is expected to be used primarily to measure prints from digital printing systems the metrics are general and may be applied to other kinds of print. This document does not provide process control aims or tolerances as these differ widely for different types of commercial applications.
Technologie graphique - Exigences pour les imprimés pour les productions industrielle et commerciale - Partie 2: Titre manque
Grafična tehnologija - Zahteve za kakovost tiska tiskovin - 2. del: Komercialni tiskarski postopki, izvedeni s tehnologijami digitalnega tiska
General Information
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS ISO TS 15311-2:2020
01-april-2020
Grafična tehnologija - Zahteve za kakovost tiska tiskovin - 2. del: Komercialni
tiskarski postopki, izvedeni s tehnologijami digitalnega tiska
Graphic technology - Print quality requirements for printed matter - Part 2: Commercial
print applications utilizing digital printing technologies
Technologie graphique - Exigences pour les imprimés pour les productions industrielle et
commerciale - Partie 2: Titre manque
Ta slovenski standard je istoveten z: ISO TS 15311-2:2018
ICS:
37.100.01 Grafična tehnologija na Graphic technology in
splošno general
SIST-TS ISO TS 15311-2:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TS ISO TS 15311-2:2020
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SIST-TS ISO TS 15311-2:2020
TECHNICAL ISO/TS
SPECIFICATION 15311-2
First edition
2018-10
Graphic technology — Print quality
requirements for printed matter —
Part 2:
Commercial print applications
utilizing digital printing technologies
Reference number
ISO/TS 15311-2:2018(E)
©
ISO 2018
---------------------- Page: 3 ----------------------
SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
---------------------- Page: 4 ----------------------
SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 General . 2
4.1.1 Applications . 2
4.1.2 Measurement . 2
4.1.3 Data reference communication . 2
4.2 Print quality measures . 3
4.2.1 Overview . 3
4.2.2 Colour and tone reproduction and surface finish. 3
4.2.3 Homogeneity . 5
4.2.4 Detail rendition capabilities . 6
4.2.5 Artefacts . 6
4.2.6 Permanence . . 6
Annex A (informative) Partial colour reference (PCR) . 8
Annex B (normative) Control strip from ISO 12647-8 . 9
Annex C (informative) .10
Annex D (informative) Specified targets and suggested tolerance ranges for digital printing
metrics in all markets .14
Bibliography .20
© ISO 2018 – All rights reserved iii
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(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 130, Graphic technology.
A list of all parts in the ISO/TS 15311 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 2018 – All rights reserved
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
Introduction
0.1 General
When producing a colour reproduction, it is important that the persons responsible for data creation,
colour separation, proofing and printing operations have previously agreed to a set of parameters
that define the visual characteristics and other technical properties of the planned print product. It
is equally important that they have agreed to the method that will be used to verify that the printed
output meets these aims and tolerances. This document identifies the minimum essential metrics and
optional metrics for analysing printing output produced for the general commercial print marketplace.
This marketplace has evolved in recent years from using classical reproduction processes such as
offset, letterpress, gravure, screen printing and flexography to include the many varied digital printing
systems that are being developed to meet a wide range of potential needs depending on how the user
chooses to prioritize speed, quality and cost. Along with and commensurate with this change has been a
shift in technical emphasis from using quality control of the printing process and expecting statistically
based predictable printing results to using colour management and other inherent measures of print
quality directly on the printed page. ISO/TS 15311-1 helps identify these metrics.
This document deals with the assessment of printed sheets and does not consider how the process of
printing the sheets is controlled. For reference, those methods for process control for conventional print
processes are described in ISO 12647-2 to ISO 12647-6. Additionally, ISO/PAS ISO 15339 establishes
principles for the use of colour characterization data as the definition of the intended relationship
between input data and printed colour in all printing applications. There is no ISO standard for process
control for digital printing; the inherent process control method is generally specified by the digital
printing system manufacturer. No matter what method is used for process control, this document may
be used to assess the printed results.
With this in mind, this document is intended to aid the printer and their customer, the print buyer,
to define the inherent quality of the sheet using targets that can be included directly on the sheet
(including the margin trim waste) or at least implied by the content of the images on the sheet itself.
It is intended to be a more direct approach to relate digital printing to visual results while achieving
the same quality levels of consistency that the industry has come to know and trust in their process
controlled printed sheet. While this document is necessary for any digital printing system output due
to the lack of a process control standard for digital printing, it could also be used to assess the resultant
quality of any printed sheet that had been printed using process control methods from any of the
classical printing processes if the printer and print buyer have previously agreed.
More importantly, because of the wide range of digital printing devices in terms of speed, quality, run
length and sheet or board size, and the equally wide range of quality needs in the various printing
market places, there presently is no cross-market agreement as to what constitutes “acceptable” quality.
This document gives guidance in applying the appropriate metrics to develop custom tolerances for
assessing printing system output, but it does not suggest specific acceptable quality levels. While it has
many of the same metrics as ISO 12647-7 and ISO 12647-8, those standards include aims and tolerances
limited to specified proofing application which are generally much tighter quality levels than normal
digital printing.
The metrics involved in this document have been selected from ISO/TS 15311-1. In a few cases if
representative metrics, for necessary aspects of judging quality such as legibility, are not included in
ISO/TS 15311-1, suggested metrics have been drawn from other sources. All specified metrics are
directly measureable on the printed sheet. Some suggested metrics, including more comprehensive
targets, which are at least indirectly measureable on another sheet printed on the same unit at
approximately the same time as the subject sheet, indicate the state that the process was in at the time
of printing. This document also includes other optional metrics for anyone who desires to analyse other
aspects of the printed sheet that are not essential to everyday transactions and which may require
special tests conducted in sophisticated laboratories. These will probably be used only to compare the
capabilities of various digital printing systems.
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
Since the role and the process of digital printing are both rapidly evolving, as indicated above, the
printer and print buyer must jointly agree on the expected quality range for each of the required tests
in advance of their printed job. Because there are many different types of digital printing equipment,
specific machine expectations must come from the manufacturers of each piece of equipment.
0.2 Identification of suitable colour metrics
When selecting the set of metrics to be included in this document, only those metrics that have a clear
definition and that correlate well with human perception are used. Since this is an area of significant
research activity we expect many new metrics to emerge in the next few years. For this reason we
anticipate the need to revise this document within a very short time scale as new metrics are tested
and found to be reliable.
In many cases the existing standards use CIE dEab rather than CIEDE2000. Although these are not
interchangeable quantities, dEab has been superseded by CIEDE2000 in ISO TC 130 standards and in
this document. Similarly, printing density is seldom used to measure colour and where the referenced
standards specify printing density we have used CIELab colour measurement.
0.3 Reporting schema
As with any parameter that is used as part of a product specification it is important for readers to
understand clearly what the metric means. For this reason ISO/TS 15311-1 includes a reporting schema
that should be followed when reporting measurements in conformance with this document. This
document includes optional reporting forms.
vi © ISO 2018 – All rights reserved
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SIST-TS ISO TS 15311-2:2020
TECHNICAL SPECIFICATION ISO/TS 15311-2:2018(E)
Graphic technology — Print quality requirements for
printed matter —
Part 2:
Commercial print applications utilizing digital printing
technologies
1 Scope
This document gives guidance to print buyers and other users of print for assessing printed products
on isotropic substrates that are typically held at a viewing distance of 30 to 50 cm. It specifies the
proper application of required, recommended and optional metrics, measurement methods and, where
appropriate, reporting requirements in the general commercial market.
Although this document is expected to be used primarily to measure prints from digital printing
systems the metrics are general and may be applied to other kinds of print.
This document does not provide process control aims or tolerances as these differ widely for different
types of commercial applications.
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 13655, Graphic technology — Spectral measurement and colorimetric computation for graphic
arts images
ISO/TS 15311-1, Graphic Technology — Requirements for printed matter for commercial and industrial
production —Part 1: Measurement methods and reporting schema
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 15311-1 and the
following 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
digital printing system
system that prints one unique iteration at a time for either variable data or classical printing
applications, including but not limited to electrophotographic and ink-jet marking engines
© ISO 2018 – All rights reserved 1
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
3.2
printing condition
components or settings used for printing that significantly constitute the final visual appearance of the
print product
Note 1 to entry: A typical printing condition comprises the printer, the substrate, the ink or toner, the used
interpreter (RIP), the colour management software, the reference printing condition to be simulated and the
print mode.
3.3
spot colour
non-process colour that is used in addition to, or in place of, a process colour and is normally applied
with a single impression
Note 1 to entry: When associated with a corporate product identity, a spot colour is also known as a brand colour.
3.4
print substrate
intended substrate to be used for production printing
4 Requirements
4.1 General
4.1.1 Applications
This document for printed output may be applied to two separate use applications:
1) Printing output from a new general commercial printing system production run. The print buyer
and the printer shall agree on aim values and tolerances for the metrics described in this document.
Aims and tolerances should be developed through use-case analysis. Measured values and ranges
for typical commercial print output for a number of regions are provided in Annex C.
2) Printing output intended to represent the capabilities of a specified digital printing system. This
shall not be implied to represent the capabilities of that model or similar models of digital printing
systems without documenting that it is representative of that group which is outside the scope of
this document. For this application no goals or tolerances are required, but aims and results shall
be reported. All care should be taken to ensure that the samples are representative of the specified
system. For multiple sheets and full press runs, sampling, measurement and reporting should be
done as described in ISO/TS 15311-1.
The application type shall be reported. It should be noted that there are no provisions for non-colour
related information such as varnishes, die cutting and other overlays.
4.1.2 Measurement
All colour measurements shall be made in accordance with ISO 13655. The measurement conditions
(M0, M1, M2 or M3) and the backing to be used (white or black backing) shall be in accordance with
those specified for the characterization data set being used, and if that is not possible, the conversion in
ISO 13655:2017, A.4 should be performed.
Metrics shall be assumed to apply to the assessment of a single printed sheet unless otherwise specified
and to the printing condition as defined in 3.2.
4.1.3 Data reference communication
All print elements shall be prepared as colorimetrically defined data. All evaluation and reference print
output shall have been targeted to pre-approved data sets. Referenced colorimetric data sets should
2 © ISO 2018 – All rights reserved
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
be in conformance with ISO 15930. The intended printing condition shall be defined by the ICC output
profile.
In order to determine a match of a printed sheet to a characterization data set or a printing condition,
according to this document, the following information shall be documented:
— the characterization data set to be used as the reference;
— the colour tolerances (if a visual match is required) and the category of colour reproduction
(“absolute” or “media-relative”) for the image content;
— the colour tolerances (if a visual match is required) for spot colours, if present;
— if a partial colour reference (PCR) is requested, information about the affected region for which the
requirements should apply, see Annex A for more information;
— additional use-case-dependent requirements, such as minimum image resolution or line width,
should be defined on an individual basis. It is recommended that guidelines provided by trade
organizations such as the GWG or PDF/X-ready are used.
4.2 Print quality measures
4.2.1 Overview
The intended viewing distance is 30 to 50 cm.
Recommended targets for all metrics in this document and a suggested appropriate range for each test
are provided in Annex D.
Metrics specified in this document, to be used for evaluation of commercial printing system output, are
defined and specified in ISO/TS 15311-1. Other properties such as legibility, which are desirable to test,
but for which a test has not been validated in Part 1, will be referenced to the best-known alternative.
For all printing system output under evaluation, the evaluation report should include the printing
device, print condition, substrate the RIP and so on.
4.2.2 Colour and tone reproduction and surface finish
4.2.2.1 General
The following requirements concern image quality attributes that are closely related to colour and
surface finish. Evaluations based on this document shall report the required evaluation metrics plus
aims and custom tolerance where applicable. Unless otherwise reported, the colour measurement
method shall be assumed to be absolute colour.
NOTE There is presently no unambiguous cross-media definition for the metric tone value range/sharpness.
An accepted industry method is ISO 12647-8:2012, 4.2.6.
4.2.2.2 Print substrate
The print substrate shall conform with print buyer specifications for type of surface, mass-per-area,
colour, fluorescence and gloss. Substrate attributes shall be reported as shown in ISO/TS 15311-1:2016,
Table 2.
© ISO 2018 – All rights reserved 3
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
4.2.2.3 Absolute colour reproduction (process colours)
For the purposes of this document, commercial printed output is separated into two types:
1) output used to establish the colorimetric match (setup) of the printing system being tested
(deviation from the intended reference printing condition) throughout the entire colour gamut
using ISO 12642-2 (or similar) colour charts and other appropriate test forms;
2) output limited to practical printing quality assessment using control strips (representative subsets
of the full colour charts) which previously were included on the output to monitor variation during
the print run.
Absolute colour reproduction testing and reporting for control strip applications (substrate, CSMax,
CSAve, CSAveNeutral) shall be required. Absolute colour reproduction testing and reporting for colour
chart applications (CCAveSurface, CCAve, CC95 %) should be required.
Targets and test methods and reporting shall be as defined in ISO/TS 15311-1. The control strip patch
requirements shall be as defined in Annex B.
The print buyer shall specify goals and tolerances for the categories listed in Table 1, as required by
the application. These requirements shall be specified in advance and suggested guidelines for these
requirements are provided in Annexes C and D.
Table 1 — Absolute colour evaluations metrics
Test type Test identification
Patch e) substrate by comparison to e) dE
00
the reference data set
Maximum colour difference for all CSMax dE
00
control strip patches
Average colour difference for control CSAve dE
00
strip patches
a
Average chromaticness difference for CSAveNeutral dCh
CMY neutral control strip patches
Average colour difference for selected CCAveSurface dE
00
surface gamut patches
Average colour difference for the CCAve dE
00
characterization chart
95th percentile for the characteriza- CC95 % dE
00
tion chart
a
∆C is the CIELAB chromaticness difference between two colours of
h
approximately the same lightness projected onto a constant lightness plane in the
CIELAB colour space. This is calculated the same way as ∆E
c
4.2.2.4 Media relative colour reproduction (process colours)
Media relative colour reproduction testing and reporting may be required for evaluating a press sheet.
Where required, targets, test methods and reporting shall be as defined in ISO/TS 15311-1.
4.2.2.5 Gloss
Gloss testing and reporting should be required for evaluating a press sheet.
For proper colour measurement and meaningful analysis the gloss of solid tone colours should be the
same category as the substrate on which they are printed (differential gloss).
If gloss is measured, it shall be measured, referenced and reported as defined in ISO/TS 15311-1:2016,
4.3.2.6.
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SIST-TS ISO TS 15311-2:2020
ISO/TS 15311-2:2018(E)
4.2.2.6 Colour deviation of multiple samples of printed matter
Colour deviation testing and reporting should be required. If required, colour deviation of printed
matter is evaluated by an average colour difference of all colours on the control strip. The average colour
difference is an average of CIE DE2000 values between the average CIE L*a*b* of all samples and CIE
L*a*b* of target colour. The samples shall be selected from printed matter in accordance with ISO/
TS 15311-1:2016, 4.2. Aims and tolerances, if required, shall be specified in advance by the print buyer for
the intended use case and suggested guidelines for these requirements are provided in Annexes C and D.
4.2.3 Homogeneity
4.2.3.1 Banding (monochrome)
A visual assessment by an experienced operator and reporting of banding should be required, and
monochrome banding testing and reporting may be required. If required, streaks and bands on 50 %
tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.2. The
target shall be 160 × 100 mm and should be 160 × 160 mm. Aims and tolerances, if required, shall be
specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.2 Large area uniformity
A visual assessment by an experienced operator and reporting of large area uniformity should be
required, and large area uniformity testing and reporting may be required. If required, large area
uniformity of C65 % M50 % Y50 % K50 %, C40 % M30 % Y30 % K30 %, C20 % M15 % Y15 % K15 %
tone values combinations shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.3. Aims and
tolerances, if required, shall be specified in advance by the print buyer for the intended use case and
suggested guidelines for these requirements are provided in Annexes C and D.
4.2.3.3 Mottle (monochrome)
A visual assessment by an experienced operator and reporting of mottle should be required, and
monochrome mottle testing and reporting may be required. If required, mottle of 70 %, 40 % and 20 %
tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.4. The
target shall be 25,4 × 25,4 mm and should be 30 × 30 mm. Aims and tolerances, if required, shall be
specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.4 Graininess (monochrome)
A visual assessment by an experienced operator and reporting of graininess should be required, and
monochrome graininess testing and reporting may be required. If required, graininess of 70 %, 40 %
and 20 % tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.5.
The target shall be 25,4 × 25,4 mm and should be 30 × 30 mm. Aims and tolerances, if required, shall
be specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.5 Show-through
Show-through testing and reporting may be required. If required, show-through shall be measured as
defined in ISO/TS 15311-1:2016, 4.3.3.6. Aims and tolerances, if required, shall be specified in advance
by the print buyer for the intended use case and suggested guidelines for these requirements are
provided in Annexes C and D.
4.2.3.6 Colour variation within printed matter
Colour variation testing and reporting should be required. If required, colour variation within
...
TECHNICAL ISO/TS
SPECIFICATION 15311-2
First edition
2018-10
Graphic technology — Print quality
requirements for printed matter —
Part 2:
Commercial print applications
utilizing digital printing technologies
Reference number
ISO/TS 15311-2:2018(E)
©
ISO 2018
---------------------- Page: 1 ----------------------
ISO/TS 15311-2:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TS 15311-2:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 General . 2
4.1.1 Applications . 2
4.1.2 Measurement . 2
4.1.3 Data reference communication . 2
4.2 Print quality measures . 3
4.2.1 Overview . 3
4.2.2 Colour and tone reproduction and surface finish. 3
4.2.3 Homogeneity . 5
4.2.4 Detail rendition capabilities . 6
4.2.5 Artefacts . 6
4.2.6 Permanence . . 6
Annex A (informative) Partial colour reference (PCR) . 8
Annex B (normative) Control strip from ISO 12647-8 . 9
Annex C (informative) .10
Annex D (informative) Specified targets and suggested tolerance ranges for digital printing
metrics in all markets .14
Bibliography .20
© ISO 2018 – All rights reserved iii
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ISO/TS 15311-2:2018(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 130, Graphic technology.
A list of all parts in the ISO/TS 15311 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 2018 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/TS 15311-2:2018(E)
Introduction
0.1 General
When producing a colour reproduction, it is important that the persons responsible for data creation,
colour separation, proofing and printing operations have previously agreed to a set of parameters
that define the visual characteristics and other technical properties of the planned print product. It
is equally important that they have agreed to the method that will be used to verify that the printed
output meets these aims and tolerances. This document identifies the minimum essential metrics and
optional metrics for analysing printing output produced for the general commercial print marketplace.
This marketplace has evolved in recent years from using classical reproduction processes such as
offset, letterpress, gravure, screen printing and flexography to include the many varied digital printing
systems that are being developed to meet a wide range of potential needs depending on how the user
chooses to prioritize speed, quality and cost. Along with and commensurate with this change has been a
shift in technical emphasis from using quality control of the printing process and expecting statistically
based predictable printing results to using colour management and other inherent measures of print
quality directly on the printed page. ISO/TS 15311-1 helps identify these metrics.
This document deals with the assessment of printed sheets and does not consider how the process of
printing the sheets is controlled. For reference, those methods for process control for conventional print
processes are described in ISO 12647-2 to ISO 12647-6. Additionally, ISO/PAS ISO 15339 establishes
principles for the use of colour characterization data as the definition of the intended relationship
between input data and printed colour in all printing applications. There is no ISO standard for process
control for digital printing; the inherent process control method is generally specified by the digital
printing system manufacturer. No matter what method is used for process control, this document may
be used to assess the printed results.
With this in mind, this document is intended to aid the printer and their customer, the print buyer,
to define the inherent quality of the sheet using targets that can be included directly on the sheet
(including the margin trim waste) or at least implied by the content of the images on the sheet itself.
It is intended to be a more direct approach to relate digital printing to visual results while achieving
the same quality levels of consistency that the industry has come to know and trust in their process
controlled printed sheet. While this document is necessary for any digital printing system output due
to the lack of a process control standard for digital printing, it could also be used to assess the resultant
quality of any printed sheet that had been printed using process control methods from any of the
classical printing processes if the printer and print buyer have previously agreed.
More importantly, because of the wide range of digital printing devices in terms of speed, quality, run
length and sheet or board size, and the equally wide range of quality needs in the various printing
market places, there presently is no cross-market agreement as to what constitutes “acceptable” quality.
This document gives guidance in applying the appropriate metrics to develop custom tolerances for
assessing printing system output, but it does not suggest specific acceptable quality levels. While it has
many of the same metrics as ISO 12647-7 and ISO 12647-8, those standards include aims and tolerances
limited to specified proofing application which are generally much tighter quality levels than normal
digital printing.
The metrics involved in this document have been selected from ISO/TS 15311-1. In a few cases if
representative metrics, for necessary aspects of judging quality such as legibility, are not included in
ISO/TS 15311-1, suggested metrics have been drawn from other sources. All specified metrics are
directly measureable on the printed sheet. Some suggested metrics, including more comprehensive
targets, which are at least indirectly measureable on another sheet printed on the same unit at
approximately the same time as the subject sheet, indicate the state that the process was in at the time
of printing. This document also includes other optional metrics for anyone who desires to analyse other
aspects of the printed sheet that are not essential to everyday transactions and which may require
special tests conducted in sophisticated laboratories. These will probably be used only to compare the
capabilities of various digital printing systems.
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ISO/TS 15311-2:2018(E)
Since the role and the process of digital printing are both rapidly evolving, as indicated above, the
printer and print buyer must jointly agree on the expected quality range for each of the required tests
in advance of their printed job. Because there are many different types of digital printing equipment,
specific machine expectations must come from the manufacturers of each piece of equipment.
0.2 Identification of suitable colour metrics
When selecting the set of metrics to be included in this document, only those metrics that have a clear
definition and that correlate well with human perception are used. Since this is an area of significant
research activity we expect many new metrics to emerge in the next few years. For this reason we
anticipate the need to revise this document within a very short time scale as new metrics are tested
and found to be reliable.
In many cases the existing standards use CIE dEab rather than CIEDE2000. Although these are not
interchangeable quantities, dEab has been superseded by CIEDE2000 in ISO TC 130 standards and in
this document. Similarly, printing density is seldom used to measure colour and where the referenced
standards specify printing density we have used CIELab colour measurement.
0.3 Reporting schema
As with any parameter that is used as part of a product specification it is important for readers to
understand clearly what the metric means. For this reason ISO/TS 15311-1 includes a reporting schema
that should be followed when reporting measurements in conformance with this document. This
document includes optional reporting forms.
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TECHNICAL SPECIFICATION ISO/TS 15311-2:2018(E)
Graphic technology — Print quality requirements for
printed matter —
Part 2:
Commercial print applications utilizing digital printing
technologies
1 Scope
This document gives guidance to print buyers and other users of print for assessing printed products
on isotropic substrates that are typically held at a viewing distance of 30 to 50 cm. It specifies the
proper application of required, recommended and optional metrics, measurement methods and, where
appropriate, reporting requirements in the general commercial market.
Although this document is expected to be used primarily to measure prints from digital printing
systems the metrics are general and may be applied to other kinds of print.
This document does not provide process control aims or tolerances as these differ widely for different
types of commercial applications.
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 13655, Graphic technology — Spectral measurement and colorimetric computation for graphic
arts images
ISO/TS 15311-1, Graphic Technology — Requirements for printed matter for commercial and industrial
production —Part 1: Measurement methods and reporting schema
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 15311-1 and the
following 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
digital printing system
system that prints one unique iteration at a time for either variable data or classical printing
applications, including but not limited to electrophotographic and ink-jet marking engines
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ISO/TS 15311-2:2018(E)
3.2
printing condition
components or settings used for printing that significantly constitute the final visual appearance of the
print product
Note 1 to entry: A typical printing condition comprises the printer, the substrate, the ink or toner, the used
interpreter (RIP), the colour management software, the reference printing condition to be simulated and the
print mode.
3.3
spot colour
non-process colour that is used in addition to, or in place of, a process colour and is normally applied
with a single impression
Note 1 to entry: When associated with a corporate product identity, a spot colour is also known as a brand colour.
3.4
print substrate
intended substrate to be used for production printing
4 Requirements
4.1 General
4.1.1 Applications
This document for printed output may be applied to two separate use applications:
1) Printing output from a new general commercial printing system production run. The print buyer
and the printer shall agree on aim values and tolerances for the metrics described in this document.
Aims and tolerances should be developed through use-case analysis. Measured values and ranges
for typical commercial print output for a number of regions are provided in Annex C.
2) Printing output intended to represent the capabilities of a specified digital printing system. This
shall not be implied to represent the capabilities of that model or similar models of digital printing
systems without documenting that it is representative of that group which is outside the scope of
this document. For this application no goals or tolerances are required, but aims and results shall
be reported. All care should be taken to ensure that the samples are representative of the specified
system. For multiple sheets and full press runs, sampling, measurement and reporting should be
done as described in ISO/TS 15311-1.
The application type shall be reported. It should be noted that there are no provisions for non-colour
related information such as varnishes, die cutting and other overlays.
4.1.2 Measurement
All colour measurements shall be made in accordance with ISO 13655. The measurement conditions
(M0, M1, M2 or M3) and the backing to be used (white or black backing) shall be in accordance with
those specified for the characterization data set being used, and if that is not possible, the conversion in
ISO 13655:2017, A.4 should be performed.
Metrics shall be assumed to apply to the assessment of a single printed sheet unless otherwise specified
and to the printing condition as defined in 3.2.
4.1.3 Data reference communication
All print elements shall be prepared as colorimetrically defined data. All evaluation and reference print
output shall have been targeted to pre-approved data sets. Referenced colorimetric data sets should
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ISO/TS 15311-2:2018(E)
be in conformance with ISO 15930. The intended printing condition shall be defined by the ICC output
profile.
In order to determine a match of a printed sheet to a characterization data set or a printing condition,
according to this document, the following information shall be documented:
— the characterization data set to be used as the reference;
— the colour tolerances (if a visual match is required) and the category of colour reproduction
(“absolute” or “media-relative”) for the image content;
— the colour tolerances (if a visual match is required) for spot colours, if present;
— if a partial colour reference (PCR) is requested, information about the affected region for which the
requirements should apply, see Annex A for more information;
— additional use-case-dependent requirements, such as minimum image resolution or line width,
should be defined on an individual basis. It is recommended that guidelines provided by trade
organizations such as the GWG or PDF/X-ready are used.
4.2 Print quality measures
4.2.1 Overview
The intended viewing distance is 30 to 50 cm.
Recommended targets for all metrics in this document and a suggested appropriate range for each test
are provided in Annex D.
Metrics specified in this document, to be used for evaluation of commercial printing system output, are
defined and specified in ISO/TS 15311-1. Other properties such as legibility, which are desirable to test,
but for which a test has not been validated in Part 1, will be referenced to the best-known alternative.
For all printing system output under evaluation, the evaluation report should include the printing
device, print condition, substrate the RIP and so on.
4.2.2 Colour and tone reproduction and surface finish
4.2.2.1 General
The following requirements concern image quality attributes that are closely related to colour and
surface finish. Evaluations based on this document shall report the required evaluation metrics plus
aims and custom tolerance where applicable. Unless otherwise reported, the colour measurement
method shall be assumed to be absolute colour.
NOTE There is presently no unambiguous cross-media definition for the metric tone value range/sharpness.
An accepted industry method is ISO 12647-8:2012, 4.2.6.
4.2.2.2 Print substrate
The print substrate shall conform with print buyer specifications for type of surface, mass-per-area,
colour, fluorescence and gloss. Substrate attributes shall be reported as shown in ISO/TS 15311-1:2016,
Table 2.
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ISO/TS 15311-2:2018(E)
4.2.2.3 Absolute colour reproduction (process colours)
For the purposes of this document, commercial printed output is separated into two types:
1) output used to establish the colorimetric match (setup) of the printing system being tested
(deviation from the intended reference printing condition) throughout the entire colour gamut
using ISO 12642-2 (or similar) colour charts and other appropriate test forms;
2) output limited to practical printing quality assessment using control strips (representative subsets
of the full colour charts) which previously were included on the output to monitor variation during
the print run.
Absolute colour reproduction testing and reporting for control strip applications (substrate, CSMax,
CSAve, CSAveNeutral) shall be required. Absolute colour reproduction testing and reporting for colour
chart applications (CCAveSurface, CCAve, CC95 %) should be required.
Targets and test methods and reporting shall be as defined in ISO/TS 15311-1. The control strip patch
requirements shall be as defined in Annex B.
The print buyer shall specify goals and tolerances for the categories listed in Table 1, as required by
the application. These requirements shall be specified in advance and suggested guidelines for these
requirements are provided in Annexes C and D.
Table 1 — Absolute colour evaluations metrics
Test type Test identification
Patch e) substrate by comparison to e) dE
00
the reference data set
Maximum colour difference for all CSMax dE
00
control strip patches
Average colour difference for control CSAve dE
00
strip patches
a
Average chromaticness difference for CSAveNeutral dCh
CMY neutral control strip patches
Average colour difference for selected CCAveSurface dE
00
surface gamut patches
Average colour difference for the CCAve dE
00
characterization chart
95th percentile for the characteriza- CC95 % dE
00
tion chart
a
∆C is the CIELAB chromaticness difference between two colours of
h
approximately the same lightness projected onto a constant lightness plane in the
CIELAB colour space. This is calculated the same way as ∆E
c
4.2.2.4 Media relative colour reproduction (process colours)
Media relative colour reproduction testing and reporting may be required for evaluating a press sheet.
Where required, targets, test methods and reporting shall be as defined in ISO/TS 15311-1.
4.2.2.5 Gloss
Gloss testing and reporting should be required for evaluating a press sheet.
For proper colour measurement and meaningful analysis the gloss of solid tone colours should be the
same category as the substrate on which they are printed (differential gloss).
If gloss is measured, it shall be measured, referenced and reported as defined in ISO/TS 15311-1:2016,
4.3.2.6.
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4.2.2.6 Colour deviation of multiple samples of printed matter
Colour deviation testing and reporting should be required. If required, colour deviation of printed
matter is evaluated by an average colour difference of all colours on the control strip. The average colour
difference is an average of CIE DE2000 values between the average CIE L*a*b* of all samples and CIE
L*a*b* of target colour. The samples shall be selected from printed matter in accordance with ISO/
TS 15311-1:2016, 4.2. Aims and tolerances, if required, shall be specified in advance by the print buyer for
the intended use case and suggested guidelines for these requirements are provided in Annexes C and D.
4.2.3 Homogeneity
4.2.3.1 Banding (monochrome)
A visual assessment by an experienced operator and reporting of banding should be required, and
monochrome banding testing and reporting may be required. If required, streaks and bands on 50 %
tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.2. The
target shall be 160 × 100 mm and should be 160 × 160 mm. Aims and tolerances, if required, shall be
specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.2 Large area uniformity
A visual assessment by an experienced operator and reporting of large area uniformity should be
required, and large area uniformity testing and reporting may be required. If required, large area
uniformity of C65 % M50 % Y50 % K50 %, C40 % M30 % Y30 % K30 %, C20 % M15 % Y15 % K15 %
tone values combinations shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.3. Aims and
tolerances, if required, shall be specified in advance by the print buyer for the intended use case and
suggested guidelines for these requirements are provided in Annexes C and D.
4.2.3.3 Mottle (monochrome)
A visual assessment by an experienced operator and reporting of mottle should be required, and
monochrome mottle testing and reporting may be required. If required, mottle of 70 %, 40 % and 20 %
tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.4. The
target shall be 25,4 × 25,4 mm and should be 30 × 30 mm. Aims and tolerances, if required, shall be
specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.4 Graininess (monochrome)
A visual assessment by an experienced operator and reporting of graininess should be required, and
monochrome graininess testing and reporting may be required. If required, graininess of 70 %, 40 %
and 20 % tone of black, cyan and magenta shall be measured as defined in ISO/TS 15311-1:2016, 4.3.3.5.
The target shall be 25,4 × 25,4 mm and should be 30 × 30 mm. Aims and tolerances, if required, shall
be specified in advance by the print buyer for the intended use case and suggested guidelines for these
requirements are provided in Annexes C and D.
4.2.3.5 Show-through
Show-through testing and reporting may be required. If required, show-through shall be measured as
defined in ISO/TS 15311-1:2016, 4.3.3.6. Aims and tolerances, if required, shall be specified in advance
by the print buyer for the intended use case and suggested guidelines for these requirements are
provided in Annexes C and D.
4.2.3.6 Colour variation within printed matter
Colour variation testing and reporting should be required. If required, colour variation within printed
matter shall be evaluated by an average colour difference of solids of the primary and secondary colours
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and representative mid-tone values (e.g. 40 %, 50 %) of the primary colours, and should be evaluated
by an average colour difference of control strip colours. The average colour difference is an average
of CIE DE2000 values between the average CIE L*a*b* of all samples and CIE L*a*b* of each sample.
The 95 percentile colour difference is a 95 percentile of CIE DE2000 values between the average CIE
L*a*b* of all samples and CIE L*a*b* of each sample. The samples shall be selected from printed matter
in accordance with ISO/TS 15311-1:2016, 4.2. Aims and tolerances, if required, shall be specified in
advance by the print buyer for the intended use case and suggested guidelines for these requirements
are provided in Annexes C and D.
4.2.4 Detail rendition capabilities
4.2.4.1 General
NOTE There is presently no unambiguous cross-media definition for the metric legibility/sharpness. An
accepted industry method is ISO 12647-8:2012, 4.2.9.
4.2.4.2 Line width
Li
...
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