ISO 15930-4:2003

INTERNATIONAL ISO
STANDARD 15930-4
First edition
2003-12-15

Graphic technology — Prepress digital
data exchange using PDF —
Part 4:
Complete exchange of CMYK and spot
colour printing data using PDF 1.4
(PDF/X-1a)
Technologie graphique — Échange de données numériques de
préimpression utilisant le PDF —
Partie 4: Échange complet de données d'impression CMYK et «spot
colour» utilisant le PDF 1.4 (PDF/X-1a)




Reference number
ISO 15930-4:2003(E)
©
ISO 2003

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ISO 15930-4:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
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ISO's member body in the country of the requester.
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Published in Switzerland

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ISO 15930-4:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms, abbreviated terms and definitions. 1
4 Notations. 4
5 Conforming files and equipment. 4
6 Technical requirements. 5
6.1 Data structure. 5
6.2 Colour. 6
6.3 Fonts. 8
6.4 File specifications . 8
6.5 Data compression . 8
6.6 Trapping. 8
6.7 PDF file identification . 8
6.8 Bounding boxes . 9
6.9 Extended graphics state. 9
6.10 PostScript XObject and the PS operator . 9
6.11 Use of the Encrypt dictionary . 10
6.12 Alternate images . 10
6.13 Annotations . 10
6.14 Actions and JavaScripts . 10
6.15 Use of the BX/EX operators . 10
6.16 Use of transparency. 10
6.17 Viewer preferences . 11
Annex A (informative) PDF feature summary . 12
Annex B (informative) Metadata.15
Bibliography . 16

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ISO 15930-4:2003(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 15930-4 was prepared by Technical Committee ISO/TC 130, Graphic technology, with the support of
ANSI Committee for Graphic Arts Technologies Standards (CGATS).
ISO 15930 consists of the following parts under the general title Graphic technology — Prepress digital data
exchange using PDF:
 Part 1: Complete exchange using CMYK data (PDF/X-1 and PDF/X-1a);
 Part 3: Complete exchange suitable for colour-managed workflows (PDF/X-3);
 Part 4: Complete exchange of CMYK and spot colour printing data using PDF 1.4 (PDF/X-1a);
 Part 5: Partial exchange of printing data using PDF 1.4 (PDF/X-2);
 Part 6: Complete exchange of printing data suitable for colour-managed workflows using PDF 1.4
(PDF/X-3).
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ISO 15930-4:2003(E)
Introduction
ISO 15930 (all parts) defines methods for the exchange of digital data within the graphic arts industry and for
the exchange of files between graphic arts establishments. It is a multi-part document where each part is
intended to respond to different workflow requirements. These workflows differ in the degree of flexibility
required. However, increasing flexibility can lead to the possibility of uncertainty or error. The goal throughout
the various parts of ISO 15930 has been to maintain the degree of flexibility required while minimizing the
uncertainty.
Many printed documents are assemblies of partial pages and/or pages created at different locations and by
different organizations. The merging of these individual elements into the final printing forme and the
subsequent printing may take place at different locations. Some of these elements may also be routed to
multiple sites for incorporation into other documents. Each of these elements is referred to in ISO 15930 as a
compound entity.
A variety of data formats and structures are used for the creation of this type of material, but with two
prevalent kinds of underlying data structures. These are vector-based data for the encoding of line art and
textual information and raster-based data for the encoding of image information, including previously
rasterized line art and textual information.
Both kinds of data structures are required along with page description information in an open electronic
workflow. The exchange of raster-based data using the TIFF/IT file format is defined in ISO 12639. The
subject of ISO 15930 is a format for the exchange of object-based data where individual objects may be in
either vector or raster data structures.
PDF/X-1a (Parts 1 and 4 of this International Standard) defines a data format and its usage to permit the
predictable dissemination of a compound entity to one or more locations as CMYK (and spot colour) data, in a
form ready for final print reproduction, by transfer of a single file. This file contains all the content information
necessary to process and render the document, as intended by the sender, coded inside a single PDF file. No
other parts, neither external files nor internally embedded files, are required or permitted. This exchange
requires no prior knowledge of the sending and receiving environments and is sometimes referred to as “blind”
exchange. It is platform- and transport-independent. Part 1 of this International Standard also includes a
second conformance level, identified as PDF/X-1, that allows the use of OPI.
These goals are accomplished by defining a specific use of the publicly available Adobe Portable Document
Format. In order to achieve a level of exchange that avoids any ambiguity in interpretation of the file, a limited
set of PDF objects that may be used is identified and restrictions to the use, or form of use, of those objects,
and/or keys within those objects are added.
This version of PDF/X-1a (Part 4 of this International Standard) amplifies and refines the information provided
in the earlier version (Part 1 of this International Standard), as follows.
 The referenced version of the Adobe Portable Document Format has been changed from 1.3 to 1.4.
 The use of OPI has been removed.
 This part of this International Standard contains only one conformance level, identified as PDF/X-1a:2003.
 The following features, introduced in PDF 1.4, have been disallowed in PDF/X-1a:2003: JBIG2,
Transparency, and Referenced PDF.
Whereas PDF/X-1a specifies the exchange of complete material, primarily as CMYK data, with all elements
present, there are circumstances when this is not appropriate. In certain workflows, some or all of the
referenced elements may be more logically present at the receiving site, or may be exchanged at a different
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ISO 15930-4:2003(E)
time. These include high-resolution contone-image files, line-art files, etc. These exchanges will generally
require prior agreement between sender and receiver. The requirements for such situations are addressed in
PDF/X-2 (Part 5 of this International Standard). Further, colour-management capabilities allow elements to be
exchanged in colour spaces other than CMYK. The requirements for such situations are addressed in
PDF/X-3 (Parts 3 and 6) of this International Standard. In addition, the requirements for intended printing
conditions using gray and RGB are included in Parts 3 and 6.
It is anticipated that a variety of products will be developed based on PDF/X, such as readers (including
viewers) and writers of PDF/X files, and products that offer combinations of these features. Different products
will incorporate various capabilities to prepare, interpret and process conforming files based on the application
needs as perceived by the suppliers of the products. However, it is important to note that a conforming reader
must be able to read and appropriately process all files conforming to a specified conformance level.
Users are cautioned that there are several different conformance levels that may be associated with PDF/X
readers and writers. Two of these are generally referred to as PDF/X-1a. These are defined in Parts 1 and 4
of this International Standard. It is recommended that these be referred to as PDF/X-1a:2001 and
PDF/X-1a:2003, respectively.
Although re-purposing of data is not a primary consideration or requirement of this part of ISO 15930,
maximum flexibility will be maintained so that future requirements for re-purposing may be accommodated.
[5]
An ongoing series of Application Notes is maintained for the guidance of developers and users of the PDF/X
family of International Standards. These Application Notes, and other documents relevant to PDF/X, are
available from NPES The Association for Suppliers of Printing, Publishing and Converting Technologies in the
NPES Standards Workroom at .

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INTERNATIONAL STANDARD ISO 15930-4:2003(E)

Graphic technology — Prepress digital data exchange using
PDF —
Part 4:
Complete exchange of CMYK and spot colour printing data
using PDF 1.4 (PDF/X-1a)
1 Scope
This part of ISO 15930 specifies the use of the Portable Document Format (PDF) Version 1.4 for the
dissemination of complete digital data, in a single exchange, that contains all elements ready for final print
reproduction. CMYK and spot-colour data are supported in any combination.
2 Normative references
The following referenced documents are indispensable for the application 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 15930-1:2001, Graphic technology — Prepress digital data exchange — Use of PDF — Part 1: Complete
exchange using CMYK data (PDF/X-1 and PDF/X-1a)
ISO 15930-3:2002, Graphic technology — Prepress digital data exchange — Use of PDF — Part 3: Complete
exchange suitable for colour-managed workflows (PDF/X-3)
ISO 15930-5:2003, Graphic technology — Prepress digital data exchange using PDF — Part 5: Partial
exchange of printing data using PDF 1.4 (PDF/X-2)
ISO 15930-6:2003, Graphic technology — Prepress digital data exchange using PDF — Part 6: Complete
exchange of printing data suitable for colour-managed workflows using PDF 1.4 (PDF/X-3)
PDF Reference: Adobe Portable Document Format, Version 1.4, Adobe Systems Incorporated — 3rd ed.
(ISBN 0-201-75839-3)
PDF Reference: Adobe Portable Document Format, Version 1.4 errata dated 2003/6/18. Available from
Internet
ICC.1:1998-09, File Format for Color Profiles, International Color Consortium. Available from Internet

3 Terms, abbreviated terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
bleed
additional printing area outside the nominal printing area necessary for the allowance of mechanical tolerance
in the trimming process
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ISO 15930-4:2003(E)
3.2
blind exchange
exchange of compound entities that requires no exchange of technical information between sender and
receiver in order for the receiver to render the printed page as intended by the sender
3.3
characterized printing condition
printing condition (offset, gravure, flexographic, direct, etc.) for which process control aims are defined and for
which the relationship between input data (printing tone values, usually CMYK) and the colorimetry of the
printed image is documented
NOTE 1 The relationship between input data (printing tone values) and the colorimetry of the printed image is
commonly referred to as characterization.
NOTE 2 It is generally preferred that the process control aims of the printing condition and the associated
characterization data be made publicly available via the accredited standards process or industry trade associations.
3.4
CMYK
subtractive process colour model where the channels are called Cyan, Magenta, Yellow and Black
3.5
complete exchange
exchange of compound entities in which all elements and element resources are present as part of a single
exchange and all of the information needed to process the compound entity is either in the compound entity or
is specified within the applicable standard and its normative references
3.6
compound entity
unit of work with all text, graphics and image elements prepared for final print reproduction and that may
represent a single page for printing, a portion of a page or a combination of pages
3.7
conformance level
identified set of restrictions and requirements with which files, readers and writers must comply
3.8
element
substructure of a compound entity relative to the current processing environment, such as a block of text, a
contone picture or an outline graphic that, by itself, comprises the smallest logical composed unit of a
compound entity
3.9
font
identified collection of graphics that may be glyphs or other graphic elements
3.10
glyph
recognizable abstract graphic symbol that is independent of any specific design
[1]
[ISO/IEC 9541-1]
3.11
glyph metrics
set of information in a glyph representation used for defining the dimensions and positioning of the glyph
shape
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ISO 15930-4:2003(E)
3.12
ICC
International Color Consortium
industry association formed to develop standardized mechanisms for colour management
3.13
ICC profile
set of colorimetric transforms prepared in accordance with ICC.1:1998
3.14
job ticket
electronic specification of process control for print production in either a published or proprietary format
NOTE Job tickets as defined here include only data intended to affect the rendered appearance of the file. See
References [3] and [4].
3.15
non-print element
element not intended for final print reproduction, including previews, preview images and all annotations of
types other than TrapNet and PrinterMark
3.16
PDF
Portable Document Format
file format defined in the PDF Reference
3.17
PDF dictionary
associative table containing key-value pairs, specifying the name and value of an attribute for objects, which is
generally used to collect and tie together the attributes of a complex object
3.18
PDF/X-1a:2001
PDF/X-1a conformance level defined in ISO 15930-1:2001
3.19
PDF/X-1a:2003
PDF/X-1a conformance level defined in this part of ISO 15930
3.20
PDF/X-2:2003
PDF/X-2 conformance level defined in ISO 15930-5:2003
3.21
PDF/X-3:2002
PDF/X-3 conformance level defined in ISO 15930-3:2002
3.22
PDF/X-3:2003
PDF/X-3 conformance level defined in ISO 15930-6:2003
3.23
print element
element intended for final print reproduction including TrapNet and PrinterMark annotations
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ISO 15930-4:2003(E)
3.24
printing tone-value
number, recorded as data in the computer, corresponding to that percentage area on a printing forme that is
intended to accept ink for transfer to the final sheet in offset lithography, or the equivalent in other printing
systems
NOTE See characterized printing condition (3.3).
3.25
process colorant
one of a set of colorants that, when printed together, produce a range of colours able to reproduce the values
specified by a colour coordinate system and which, in the context of this part of this International Standard,
always refers to C, M, Y, or K
NOTE See CMYK (3.4).
3.26
reader
software application that is able to read and appropriately process files
3.27
spot colour
single colorant, identified by name, whose printing tone-values are specified independently from the colour
values specified in a colour coordinate system
3.28
trapping
modification of boundaries of colour areas to account for dimensional variations in the printing process by
overprinting in selected colours at the boundaries between colours that might inadvertently be left uncoloured
due to normal variations of printing press registration
NOTE Trapping is sometimes referred to as chokes and spreads or grips. This is not the same as ink trapping.
3.29
writer
software application that is able to write files
4 Notations
PDF operators, PDF keywords, the names of keys in PDF dictionaries, and other predefined names are
written in a bold sans serif type font; for example, the key Trapped.
Operands of PDF operators or values of dictionary keys are written in an italic sans serif font; for example the
False value for the Trapped key.
For the purposes of this part of this International Standard, references to the “PDF Reference” are to the PDF
Reference: Adobe Portable Document Format corrected by the errata dated 2003/6/18 (see Clause 2).
5 Conforming files and equipment
This part of this International Standard defines the use of the PDF file format for the exchange of digital data
representing a compound entity.
A conforming PDF/X-1a file is a PDF file in which those features necessary for the exchange of a compound
entity are in accordance with this part of this International Standard. A conforming file may also include other
valid PDF features that do not affect final print reproduction of the compound entity.
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ISO 15930-4:2003(E)
Neither the version number in the header of a PDF file, nor the value of the Version key in the Catalog of a
PDF file shall be used in determining whether a file is in accordance with this part of this International
Standard.
A conforming PDF/X-1a writer is a software application that shall be able to write files in accordance with the
requirements of this part of this International Standard. A conforming PDF/X-1a reader is a software
application that shall be able to read and appropriately process all conforming PDF/X-1a files as defined in
this part of this International Standard. A conforming PDF/X-1a reader shall also be able to read and process
all files in accordance with the PDF/X-1a conformance level specified in ISO 15930-1:2001 having a value of
(PDF/X-1:2001) for the GTS_PDFXVersion key, and (PDF/X-1a:2001) for the GTS_PDFXConformance key
in the Info dictionary and that also conform to 6.16 of this part of this International Standard. The processing
of files conforming to the PDF/X-1 conformance level as specified in ISO 15930-1:2001 by a PDF/X-1a reader
shall be at the discretion of the application software.
NOTE The ability to read files prepared in accordance with the PDF/X-1a:2001 conformance level as specified in
ISO 15930-1:2001, the predecessor to this part of ISO 15930, is important to preserve compatibility. Users are cautioned
that there are several different conformance levels that may be associated with PDF/X readers and writers. Two of these
are generally referred to as PDF/X-1a. These are defined in Parts 1 and 4 of this International Standard. These are
referred to as PDF/X-1a:2001 and PDF/X-1a:2003, respectively.
Although PDF Reference permits compliance with earlier versions of PDF, features described in versions of
the PDF specification earlier than 1.4, but not described in PDF Reference, should not be used in a
conforming PDF/X-1a file. Such features may be ignored by a PDF/X-1a reader.
All conforming readers shall parse all PDF files but may ignore those features not required by this part of
ISO 15930. A reader may ignore an annotation’s Print flag except for those in a TrapNet annotation.
Rendering of conforming files shall be performed as defined in the PDF Reference and as restricted by this
part of ISO 15930. To the extent that the PDF Reference and this part of this International Standard permit
more than one rendering of a conforming file, a conforming reader may use embedded job-ticket or metadata
information to control the rendering of the file more precisely.
EXAMPLE 1 (Trapping) If a conforming PDF/X-1a file specifies Trapped=False, a conforming reader might use job-
ticket information to determine details of how the file is to be trapped. If the file specifies Trapped=True, a conforming
reader is required to ignore any trapping information in an embedded job ticket.
EXAMPLE 2 (Screening) A conforming reader may use embedded job-ticket information to determine the screening to
be used to render the file. Note that a conforming PDF/X-1a reader is permitted to ignore screening information in the
PDF/X-1a file (see 6.9). A conforming reader might use screening data from the PDF/X-1a file, from the job ticket, or from
local system defaults.
6 Technical requirements
6.1 Data structure
A PDF/X-1a file consists of four sections: header, body, cross-reference table, and trailer. The body of a
PDF/X-1a file contains a sequence of numbered objects (such as numbers, names, strings, dictionaries and
streams) representing the text characters, graphics, images and their associated resources describing the
compound entity being exchanged. The PDF features which shall be required are specified in 6.2 to 6.17,
inclusively and are summarized in Annex A. These features shall be used as prescribed in the PDF Reference
and as further restricted by this part of this International Standard.
In order to achieve the requirements of a blind exchange, the use of a pre-separated PDF file (where the
separations for each page are described as separate page objects, each painting only a single colorant) shall
not be permitted.
NOTE 1 This does not prohibit the use of pre-separated workflows in which the separations of a page are combined
into a single PDF page object.
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ISO 15930-4:2003(E)
A PDF/X-1a file may contain two classes of elements: those intended for final print reproduction (print
elements), and those not intended for final print reproduction (non-print elements). All components of a
compound entity intended for complete exchange in compliance with this part of this International Standard
shall be contained in the body of a single PDF/X-1a file.
“Complete” means the exchanged files shall include
 all PDF resources (listed in the PDF Reference) used in the file, including all fonts, font metrics, font
encodings, and colour space resources;
and
 all print elements, properly prepared for a single characterized printing condition.
NOTE 2 For partial exchange of compound entities, refer to PDF/X-2 (ISO 15930-5:2003). For complete exchange
using colour-managed data, refer to PDF/X-3 (ISO 15930-3:2002 and ISO 15930-6:2003).
6.2 Colour
6.2.1 General
Non-print elements may make use of any PDF colour space and the provisions of 6.2.2 to 6.2.4, inclusive, do
not apply to non-print elements. Print elements shall be exchanged as CMYK data, gray scale data, or
separation colour data. The CMYK and gray scale printing tone values in print elements shall be colour-
corrected and adjusted for a single characterized printing condition prior to exchange. This characterized
printing condition is defined by either a named condition or an ICC output profile.
Print elements in a PDF/X-1a file may be defined in DeviceCMYK, DeviceGray, Separation, DeviceN,
Indexed and Pattern colour spaces as specified and restricted by 6.2.2 to 6.2.4.
NOTE PDF Reference allows a device colour space for which a matching default colour space is present to be
interpreted as device-independent using the colorimetric data of the default colour space. The default colour space
mechanism is an indirect method of specifying a colour space. Therefore, for PDF/X-1a files, it is not permissible to have a
default colour space defined for any printing element.
6.2.2 Identification of characterized printing condition
The characterized printing condition (i.e. the process c
...