ISO 20616-2:2020

INTERNATIONAL ISO
STANDARD 20616-2
First edition
2020-03
Graphic technology — File format for
quality control and metadata —
Part 2:
Print Quality eXchange (PQX)
Technologie graphique — Format de fichier pour le contrôle qualité
et les métadonnées —
Partie 2: PQX (Print Quality eXchange)
Reference number
ISO 20616-2:2020(E)
©
ISO 2020

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ISO 20616-2:2020(E)

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ISO 20616-2:2020(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 Extensibility . 3
5.2.1 General. 3
5.2.2 TagCollection . 3
5.2.3 CustomResources . 3
5.3 Employing CxF . 3
5.4 PQX quality reporting . 4
5.4.1 Overview . 4
5.4.2 PQX element . 4
5.4.3 PQXInfo element. 4
5.4.4 PrinterInfo element . 5
5.4.5 PressRunInfo element . 5
5.4.6 RunLength element . 6
5.4.7 InkCollection/Ink element . 7
5.4.8 ReporterCollection/Reporter element . 7
5.4.9 QualityServiceProvider element . 8
5.4.10 PrinterQA element . 8
5.4.11 AutomatedPressControl element . 9
5.4.12 CustomerItemCollection element . 9
5.4.13 Customer element .10
5.4.14 SampleCollection element .11
5.4.15 ColorReport element .11
5.4.16 MeasurementSet element .12
5.4.17 RegistrationReport element .14
5.4.18 VarianceReport element .14
5.4.19 ChannelReport element .15
5.4.20 DefectReport/DefectSet element .16
5.4.21 DefectData element .17
5.4.22 BarcodeReport element .18
5.4.23 Barcode parameter reporting attribute .18
5.4.24 Barcode1DEntry element .18
5.4.25 Traditional1DVerification element .19
5.4.26 Barcode2DEntry element .21
5.4.27 FPDDetails element .22
5.4.28 Traditional2DVerification element .23
5.4.29 CxFSampleData element .25
5.4.30 CxFReferenceData element .25
5.4.31 DefectImageData element .25
5.4.32 TagCollection element .25
5.4.33 CustomResources element .26
Annex A (normative) ISO 20616-2 XML schema .27
Annex B (informative) PQX principles and concepts .28
Annex C (informative) Samples .30
Bibliography .33
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ISO 20616-2:2020(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 20616 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.
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ISO 20616-2:2020(E)

Introduction
ISO 20616 defines standard XML schemas designed to enable the digital exchange of print quality data
and metadata between trading partners within the graphic arts supply chain. In the past, a number
of different non-standard data formats have been used to communicate print quality metrics. It is a
general observation that many of these existing non-standard data formats describe similar types of
information. Existing standard data formats cover either too much or too little scope to address industry
requirements. Hence, there is an industry need for a single, standard concise set of data formats for the
communication of print quality.
Each part of ISO 20616 is intended to stand alone, but may be used in conjunction with each other,
should that option be chosen. The goal of ISO 20616 is to maintain the degree of flexibility required by
print buyers for all kinds of print generated for all purposes from any print device while minimizing the
uncertainty of the data exchanged.
This document is intended to facilitate the one-way transmission of performance data for one or
more printed samples, for one or more brands or products from a single press run from print service
providers to relevant stakeholders and print buyers; thus, allowing them to assess and track relevant
business, production, colour and quality data of printed materials of all forms. PQX is only intended to
transmit raw quality data. The PQX file intentionally excludes tolerance and evaluative information,
allowing the receiver to determine acceptability by applying their own scale and tolerance values. PQX
incorporates colour using the same data containers that are defined in ISO 17972-4 (CxF3_Core.xsd).
While PQX and CxF are different formats with different parsing requirements, developers can use the
same strategies for reading and writing colour data in a PQX file that they use for reading and writing
colour data in a CxF file. PQX is compatible with both spectral and non-spectral colour data.
Some portions of this document are available as electronic files at http:// standards .iso .org/ iso/ 20616/
-2/ ed -1/ en
— ISO20616-2PQX.xsd
— ISO20616-2pqx_lines.pdf (a printable version of the PRX XML schema with reference line numbers)
— ISO20616-2SchemaDoc.pdf (Schema diagrams and documentation)
— PQX_MasterSampleA.pqx
— PQX_MasterSampleA.pdf (a printable version of Sample A with reference line numbers)
— PQX_MasterSampleB.pqx
— PQX_MasterSampleB.pdf (a printable version of Sample B with reference line numbers)
NOTE The spelling of fields in PQX were designed to match the spelling of fields taken from ISO 17972-1
and are not altered from that used in the normative reference. A specific example is the use of the word “color”
instead of “colour”.
It should be noted that Idealliance, Inc. the original creator of the PQX file format, claims no intellectual
property rights, neither patent nor copyright, to the materials used in this document.
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INTERNATIONAL STANDARD ISO 20616-2:2020(E)
Graphic technology — File format for quality control and
metadata —
Part 2:
Print Quality eXchange (PQX)
1 Scope
This document specifies an extensible file format in conformity with W3C Extensible Markup Language
(XML) 1.0, for the exchange of print quality data and metadata between quality control applications
including but not limited to colour measurement, process control and quality management systems.
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, Graphic technology — Colour data exchange format — Part 1: Relationship to CxF3 (CxF/X)
ISO 17972-3, Graphic technology — Colour data exchange format (CxF/X) — Part 3: Output target data
(CxF/X-3)
Extensible Markup Language (XML) 1.0 (Fifth Edition), World Wide Web Consortium (W3C), W3C
Recommendation, 26 November 2008. Available at https:// www .w3 .org/ TR/ 2008/ REC -xml -20081126/
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
CxF
electronic exchange format for colour and process control data (and the associated metadata necessary
for its proper interpretation)
3.2
press run
continuous operation of a printing press for a single job
3.3
print buyer
name of the customer or entity purchasing printing services and products
3.4
print defect
imperfection that impairs worth or utility of a printed item that stems from a wide array of potential
causes and varies from printing method to printing method
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ISO 20616-2:2020(E)

3.5
printer
name of the print service provider responsible for printing items purchased by a print buyer (3.3)
3.6
XML
Extensible Markup Language
set of rules recommended by the World Wide Web Consortium (W3C) for encoding documents in a
digital format which is both human-readable and machine-readable
3.7
XML attribute
attribute
XML construct included within the start tag of an XML element (3.8) that modifies, or provides
descriptive metadata about, that element’s content
3.8
XML element
element
data structure including a start tag, an end tag, data between these tags, and, possibly, a set of XML
attributes (3.7)
[SOURCE: ISO 13584-32:2010, 3.22, modified — Added admitted term.]
3.9
XML root element
root element
single XML element that encloses all the other elements and is therefore the sole parent element to all
the other elements
3.10
XML schema
language for describing the structure and constraining the contents of XML documents
[SOURCE: ISO 25720:2009, 4.32]
3.11
XML schema parser
application that is capable of validating document schemes (content and structure) and descriptor data
types against their schema definition
[SOURCE: ISO/IEC 23001-1:2006, 3.2.71]
4 Symbols and abbreviated terms
The following documentation conventions are used.
— Names of XML elements are shown in bold type; for example, SampleCollection.
— Names of XML attributes are shown in italics; for example, @DisplayName.
XML XPaths are used to identify XML elements. For example, SampleCollection/Sample refers to an
element (Sample) that is a child of another element (SampleCollection).
Similarly, XML XPaths are used to refer to XML attributes. For example, CustomerItem/@Id refers to
an attribute (Id) of an element (CustomerItem).
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ISO 20616-2:2020(E)

5 Requirements
5.1 General
The following general requirements shall be met when using PQX XML to exchange print quality data
and metadata.
— The exchange of PQX print quality data and metadata shall conform to Extensible Markup Language
(XML) 1.0 (Fifth Edition).
— If PQX quality data are exchanged as a standalone file, the file extension shall be “.pqx”.
— The root element of ISO 20616-2 print quality data shall be a single PQX element.
— A valid PQX element shall contain the required namespace information in the root element: ( xmlns:p qx = ”http:// idealliance .org/ pqx” > ) followed by the XML elements and XML attributes
specified by ISO20616-2PQX.xsd.
— If colour quality data are being exchanged, the PQX root element shall contain the required
namespace information for CxF, “xmlns: cc = ”http:// colorexchangeformat .com/ CxF3 -core”.
PQX quality data should be validated using an XML schema parser employing the XML schema file
ISO20616-2PQX.xsd. The requirements for utilization of the ISO20616-1PQX schema shall be as specified
in Annex A.
5.2 Extensibility
5.2.1 General
To provide for extensibility for this document, the specification includes two blocks modelled directly
from the extensibility provided by CxF/X; TagCollection and CustomResources.
5.2.2 TagCollection
TagCollection may only be used to insert additional application-specific child elements into a PQX data
structure at the agreement of all trading partners. See 5.4.32.
NOTE Use of TagCollection is highly discouraged.
5.2.3 CustomResources
CustomResources may only be used to insert additional application-specific data models into a PQX
data structure at the agreement of all trading partners. See 5.4.33.
NOTE Use of CustomResources is highly discouraged.
5.3 Employing CxF
ISO 17972-1 shall be used to exchange print quality colour data and metadata. The following
requirements shall be met when using the CxF schema.
— Only Core CxF data shall be employed as the data store for colour requirements data.
— CxF shall be employed as a complete CxF hierarchy.
NOTE Retaining < c c: C x F > as the root element ensures direct importability from colour measurement
devices.
— CxF should only be used to customize CxF if specified by a business agreement among
trading partners.
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ISO 20616-2:2020(E)

— CxF should only be used to customize CxF if specified by a business
agreement among trading partners.
— CxF < cc:P hysicalAttributes > < cc: C u s t om At t r ibut e S t r i n g > and < cc:
CustomAttributeValue > should only be used to customize CxF if specified by a business agreement
among trading partners.
— Non-appropriate CxF elements (listed above) may be written into a PQX quality report but should
only be processes by receiving systems if specified by a business agreement among trading partners.
5.4 PQX quality reporting
5.4.1 Overview
The ISO20616-2PQX schema provides the rules for the order, occurrence and datatypes for the fields that
make up a print quality report. The ISO20616-2PQX schema is the immutable specification. Additional
requirements that cannot be specified by an XML schema are found in the following subclauses.
NOTE A printable version of the ISO20616-2PQX schema with reference line numbers is available at http://
standards .iso .org/ iso/ 20616/ -2/ ed -1/ en) to enable referencing of element definitions by this document. See
Annexes B and C for additional information.
5.4.2 PQX element
The PQX element is the root element of a print quality data exchange. The PRX element shall be used
to specify a print buyer’s print quality report. The PQX element shall conform to rules specified by
ISO20616-2PQX.xsd (lines 10–30).
Table 1 provides for references to the specifications for fields that make up the PQX element.
Table 1 — PQX field specifications
Field name Normative specifications
PQXInfo See 5.4.3.
PrinterInfo See 5.4.4.
PressRunInfo See 5.4.5.
InkCollection See 5.4.6.
ReporterCollection See 5.4.8.
CustomerItemCollection See 5.4.10.
SampleCollection See 5.4.12.
CxFSampleData See 5.4.29.
CxFReferenceData See 5.4.30.
DefectImageData See 5.4.31.
TagCollection See 5.4.32.
CustomResources See 5.4.33.
5.4.3 PQXInfo element
The PQXInfo element shall be used to identify the instance of the print quality report being exchanged.
The PQXInfo element shall conform to rules specified by ISO20616-2PQX.xsd (lines 35–47). Table 2
provides definitions and usage rules for each child element of PQXInfo.
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ISO 20616-2:2020(E)

Table 2 — PQXInfo element definition and usage rules
Name Definition Usage rules
PQXDate The PQXDate element shall be used The PQXDate element shall conform to
to identify date or date/time this PQX rules specified by ISO20616–2PQX.xsd
data was generated. (lines 51–55).
PQXId The PQXId element shall be used to The PQXId element shall conform to rules
provide an identifier (unique in the specified by ISO20616–2PQX.xsd
context of system generated identifiers (lines 59–63).
assigned on the specified PQXDate) for
this print quality report.
PQXSoftware-Version PQXSoftware-Version shall be used to The PQXSoftware-Version element shall
identify the software and version that conform to rules specified by ISO20616–
generated this print quality report. 2PQX.xsd (lines 67–71).
NOTE Concatenation of the PQXDate, PQXId and PQXSoftware-Version can make up a unique identifier for this print
quality data report.
5.4.4 PrinterInfo element
The PrinterInfo element shall be used to identify information about the printer generating the print
quality report. The PrinterInfo element shall conform to rules specified by ISO20616-2PQX.xsd
(lines 245–258). Table 3 provides definitions and usage rules for each child element of PrinterInfo.
Table 3 — PrinterInfo definition and usage rules
Name Definition Usage rules
ParentCompany The ParentCompany element shall The ParentCompany element shall con-
be used to identify the company that form to rules specified by ISO20616–2PQX.
controls a smaller, entity such as a xsd (lines 155–159).
printer or quality service provider.
Printer The Printer element shall be used to The Printer element shall conform to
provide the name of the print service rules specified by ISO20616–2PQX.xsd
provider responsible for printing (lines 262–266).
items purchased by a print buyer.
LocationDesignator The LocationDesignator element The LocationDesignator element shall
shall be used to provide a designation conform to rules specified by ISO20616–
for the location of a company or party 2PQX.xsd (lines 171–175).
as a second level of identification for
that company or party.
ContactDesignator The ContactDesignator element The ContactDesignator element shall con-
shall be used to provide a designation form to rules specified by ISO20616–2PQX.
for information required to communi- xsd (lines 179–183).
cate with a business entity.
NOTE 1 LocationDesignator can be a unique identifier, city/state/country designation, postal code, geographic
coordinates or simply be a designator code employed by the printer. This element is purposefully flexible to facilitate broad
printer adoption.
NOTE 2 ContactDesignator can be email, street address, phone, fax, etc. or simply be a designator code employed by the
printer. This element is purposefully flexible to facilitate broad printer adoption.
5.4.5 PressRunInfo element
The PressRunInfo element shall be used to provide descriptive information about the press run. The
PressRunInfo element shall conform to rules specified by ISO20616-2PQX.xsd (lines 270–290). Table 4
provides definition and usage rules for each child element of PressRunInfo.
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ISO 20616-2:2020(E)

Table 4 — PressRunInfo definition and usage rules
Name Definition Usage rules
DatePrinted The DatePrinted element shall be DatePrinted element shall conform to
used to s identify date or date/time rules specified by ISO20616–2PQX.xsd
this pressrun was conducted. (lines 294–298).
PrinterLotId The PrinterLotId element shall be The PrinterLotId element shall conform
used to provide the identifier used by to rules specified by ISO20616–2PQX.xsd
the printer for the press run. (lines 302–306).
RunLength See 5.4.6
PrintMethod The PrintMethod element shall be The PrintMethod element shall conform
used to specify the mechanism by to rules specified by ISO20616–2PQX.xsd
which customer items were printed. (lines 335–339).
PrintSide The PrintSide element shall be used The PrintSide element shall conform to
to specify the side of the substrate rules specified by ISO20616–2PQX.xsd
where the customer image(s) is/are (lines 343–348).
printed.
PressLine The PressLine element shall be used The PressLine element shall conform to
to specify the line within a print shop rules specified by ISO20616–2PQX.xsd
where the press run took place. . (lines 352–356).
PressOperator The PressOperator element shall be The PressOperator element shall conform
used to identify the person running to rules specified by ISO20616–2PQX.xsd
the press. (lines 360–365).
Shift The Shift element shall be used to The Shift element shall conform to
specify the printer workforce period rules specified by ISO20616–2PQX.xsd
when the press run took place. (lines 369–373).
PrinterComments The PrinterComments element shall The PrinterComments element shall con-
be used to provide any additional form to rules specified by ISO20616–2PQX.
comments the printer may have about xsd (lines 377–381).
the press run.
PrinterJobDescription The PrinterJobDescription el- The PrinterJobDescription element shall
ement shall be used to provide a conform to rules specifi
...