ISO 17972-4:2018
(Main)Graphic technology — Colour data exchange format (CxF/X) — Part 4: Spot colour characterisation data (CxF/X-4)
Graphic technology — Colour data exchange format (CxF/X) — Part 4: Spot colour characterisation data (CxF/X-4)
ISO 17972-4:2018 defines an exchange format for spectral measurement data of inks to provide a means to characterise spot colour inks to allow reliable printing and proofing of products that have been designed using these inks. Only isotropic (paper-like) substrates are within the scope of this document, which is limited to application areas where the same ink and paper combination that has been characterised is used when printing. ISO 17972-4:2018 describes the use of a CustomResource element within the CxF framework to define a minimum and recommended set of data for exchange.
Technologie graphique — Échange des données de couleur en utilisant CxF — Partie 4: Données de caractérisation des points de couleur (CxF/X-4)
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 17972-4
Second edition
2018-01
Graphic technology — Colour data
exchange format (CxF/X) —
Part 4:
Spot colour characterisation data
(CxF/X-4)
Technologie graphique — Échange des données de couleur en
utilisant CxF —
Partie 4: Données de caractérisation des points de couleur (CxF/X-4)
Reference number
ISO 17972-4:2018(E)
©
ISO 2018
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ISO 17972-4:2018(E)
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ISO 17972-4:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Requirements . 3
5.1 General . 3
5.2 Conformance levels . 3
5.3 Characterisation chart preparation . 3
5.3.1 General. 3
5.3.2 Printed patches . 4
5.3.3 Substrate and ink identification . 5
5.3.4 Preparation of black region . 5
5.3.5 Measurements . 5
5.4 Measurement communication . 5
5.4.1 General. 5
5.4.2 Structure . 5
5.4.3 FileInformation element . 6
5.4.4 Core resources . 6
5.4.5 CustomResources . 8
Annex A (informative) XML schema for CxF/X-4 CustomResource .10
Annex B (informative) Examples of CxF/X-4 documents .11
Annex C (informative) CxF Core schema .12
Bibliography .13
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ISO 17972-4:2018(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 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: www .iso .org/ iso/ foreword .html
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
This second edition cancels and replaces the first edition (ISO 17972-4:2015), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— electronic files for Annexes A and B, available at http:// standards .iso .org/ iso/ 17972/ -4/ ed -2/ en,
have been corrected;
— 5.3.2 has been clarified that the same set of patches shall be printed on black and substrate;
— that the black region may now be printed with a combination of inks has been added;
— minor clarifications and editorial corrections have been added.
A list of all parts in the ISO 17972 series can be found on the ISO website.
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ISO 17972-4:2018(E)
Introduction
The ISO 17972 series defines methods for the exchange of measurement data and associated metadata
within the graphic arts industry and for the exchange of files between graphic arts users. It is a multi-
part document where each part is intended to respond to different workflow requirements. The goal
throughout the various parts of ISO 17972 has been to maintain the degree of flexibility required while
minimizing the uncertainty of the data exchanged.
ISO 17972-1 defines the use of the publicly available Colour Exchange Format, version 3 (CxF3), for
prepress data exchange and verification.
ISO 17972-2 defines the use of a CustomResource for the creation of scanner target data.
ISO 17972-3 defines the use of a CustomResource when exchanging data from ISO 12642-1 and
ISO 12642-2.
Communication of printing characteristics of inks is essential in order to ensure that a printed product
has the appearance desired by a print buyer or brand manager. Traditionally, inks are thought of as
being either process inks or spot inks. The term “process inks” is used to describe a set of inks that are
frequently used in combination on a printing press (often cyan, magenta, yellow and black). Process
inks are generally characterised in combination and the measurement data for combinations of inks is
the subject of ISO 17972-3.
This document covers the use of CxF when exchanging spot colour characterisation data. There are
many proprietary formats for this communication and it is hoped that this document will provide a
more reliable means for the communication of spot colour characterisation data. It is usually impractical
to print and measure combinations of spot colour inks. Instead, each ink is characterised in conjunction
with a print substrate by means of its spectral characteristics and ink opacity.
In some cases, multiple impressions of single or multiple spot inks can be used; details of these inks
and the production method used are not provided in this document. Similarly, the way in which an ink
is produced is also outside of the scope. Information of this kind can be included using standard CxF
extension mechanisms.
The measurement of metallic, pearlescent or fluorescent colours might require additional or extended
data fields in addition to those described in this document in order to be sufficient to fully characterise
these types of ink.
X-Rite Inc., the original creator of the CxF file format, claims no intellectual property rights to the
materials used in this document.
The following files are part of this document and are available at http:// standards .iso .org/ iso/ 17972/
-4/ ed -2/ en:
— CxF3_Core.xsd;
— CxF3_Core_Schema_diagram.pdf;
— ISO17972-4_CxFX-4_Example 1.xml;
— ISO17972-4_CxFX-4_Example 2.xml;
— ISO17972-4_CxFX-4_schema.xsd.
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INTERNATIONAL STANDARD ISO 17972-4:2018(E)
Graphic technology — Colour data exchange format
(CxF/X) —
Part 4:
Spot colour characterisation data (CxF/X-4)
1 Scope
This document defines an exchange format for spectral measurement data of inks to provide a means to
characterise spot colour inks to allow reliable printing and proofing of products that have been designed
using these inks. Only isotropic (paper-like) substrates are within the scope of this document, which is
limited to application areas where the same ink and paper combination that has been characterised is
used when printing.
This document describes the use of a CustomResource element within the CxF framework to define a
minimum and recommended set of data for exchange.
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 17972-1:2015, Graphic technology — Colour data exchange format — Part 1: Relationship to CxF3 (CxF/X)
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
ColorSpecification
information about the ColorValue (3.2) including its source (measurement specifications),
illuminant/observer calculation method (tristimulus specifications), and physical attributes of the
objects (3.5) (size, quantity, finish, etc.)
[SOURCE: ISO 17972-1:2015, 3.1.1]
3.2
ColorValue
defined colour space type that can hold values and associated information related to that specific type
of device independent colour space
[SOURCE: ISO 17972-1:2015, 3.1.2 — modified to comply with ISO/IEC Directives, Part 2, 2016, 16.5.5.]
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ISO 17972-4:2018(E)
3.3
CustomResources
additional information not included in the CxF3 Core about colour objects and the file itself that is
considered application specific in nature and not generally of use to all other applications
[SOURCE: ISO 17972-1:2015, 3.1.3 — modified to comply with ISO/IEC Directives, Part 2, 2016, 16.5.5.]
3.4
element content
XML text between the start tag and end tag of an element
[SOURCE: ISO 16684-1:2012, 3.2]
3.5
object
thing used to identify each specific “colour item” that is being described
[SOURCE: ISO 17972-1:2015, 3.1.5 — modified to comply with ISO/IEC Directives, Part 2, 2016, 16.5.5.]
3.6
resources
information about each colour object that is of interest to all readers of the CxF file
Note 1 to entry: This is also referred to as the “CxF3 Core”. It is defined by the CxF3-Core namespace schema.
[SOURCE: ISO 17972-1:2015, 3.2.4]
3.7
schema
XML document conforming to the specifications established by the World Wide Web Consortium that
defines the structure of a class of XML documents
[SOURCE: ISO 17972-1:2015, 3.2.5]
3.8
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
3.9
tint level
percentage value in the range 0 to 100 that indicates how much of a marking substance (e.g. ink, toner)
should be applied to a printed region
3.10
eXtensible Markup Language
XML
set of rules for encoding documents electronically
[SOURCE: ISO 17972-1:2015, 3.2.6 — modified]
4 Symbols and abbreviated terms
The following documentation conventions are used.
— Names of XML elements are shown in bold type, for example Resources.
— Names of XML attributes are shown in italics, for example SpotColorName.
— XML XPaths are used to identify XML elements. For example, container/contained refers to an
element (contained) that is a child of another element (container).
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ISO 17972-4:2018(E)
— Similarly, XML XPaths are used to refer to XML attributes. For example, element1/@Name refers to
an attribute (Name) of an element (element1).
5 Requirements
5.1 General
CxF/X-4 files conform to the requirements of ISO 17972-1 and the CoreResource element may be
validated as described in Annex C.
Details as to how the CustomResource element may be validated are provided in Annex A and some
examples are described in Annex B.
The status of Annexes A, B and C is informative.
5.2 Conformance levels
This specification defines three conformance levels identified as CxF/X-4, CxF/X-4a and CxF/X-4b.
These conformance levels allow different methods of spot colour communication in common use to be
described.
a) CxF/X-4 Full Characterisation. The data provided by CxF/X-4 allows the colour and opacity of the
ink to be specified. This is particularly important in situations where an accurate proof of the spot
ink printed on top of other content is to be made.
b) CxF/X-4a Single Background Characterisation. There are situations where it is useful to be able
to communicate characterisation data for an ink where the ink will only be printed on a single
background and so can be characterised using a single set of spectral measurements.
c) CxF/X-4b Single Patch Characterisation. There are situations where it is useful to be able to
communicate characterisation data for an ink where the ink will always be printed as a solid and so
can be characterised using a single spectral measureme
...
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