ISO/DIS 15930-3

Graphic technology -- Prepress digital data exchange -- Use of PDF

Technologie graphique -- Échange de données numériques de préimpression -- Emploi de PDF

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD ISO/DIS 15930-3
ISO/TC 130 Secretariat: DIN
Voting begins on Voting terminates on
2002-12-19 2003-05-19

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION

Graphic technology — Prepress digital data exchange —
Use of PDF —
Part 3:
Complete exchange suitable for colour-managed workflows
(PDF/X-3)
[Revision of first edition (ISO 15930-3:2002)]

Technologie graphique — Échange de données numériques de préimpression — Emploi de PDF —

Partie 3: Échange de fichiers complets aptes à la gestion des couleurs (PDF/X-3)
ICS 35.240.30; 37.100.99

In accordance with the provisions of Council Resolution 15/1993 this document is circulated

in the English language only.

Conformément aux dispositions de la Résolution du Conseil 15/1993, ce document est

distribué en version anglaise seulement.

To expedite distribution, this document is circulated as received from the committee

secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at

publication stage.

Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du

secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au

Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE REFERRED TO

AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.

IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT

INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO WHICH

REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
© International Organization for Standardization, 2002
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ISO/DIS 15930-3 (E)
Contents Page

Foreword ........................................................................................................................................................................ iv

Introduction..................................................................................................................................................................... v

1 Scope........................................................................................................................................................................... 1

2 Normative references................................................................................................................................................ 1

3 Terms and definitions ............................................................................................................................................... 1

4 Symbols and notations ............................................................................................................................................. 4

5 Conformance .............................................................................................................................................................. 4

6 Technical requirements ............................................................................................................................................ 5

Annex A (Informative) PDF feature summary ........................................................................................................... 11

Annex B (Informative) Metadata ................................................................................................................................. 14

Bibliography.................................................................................................................................................................. 15

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ISO/DIS 15930-3(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.

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.

This part of ISO 15930 was prepared by Technical Committee ISO/TC 130, Graphic technology.

Attention is drawn to the possibility that some of the elements of this part of ISO 15930 may be the subject of patent rights.

ISO shall not be held responsible for identifying any or all such patent rights.

ISO 15930 consists of the following parts, under the general title Graphic technology — Prepress digital data exchange —

Use of PDF:
Part 1: Complete exchange using CMYK and spot colour data (PDF/X-1a)
Part 2: Partial exchange (PDF/X-2)
Part 3: Complete exchange suitable for colour-managed workflows (PDF/X-3)
Annexes A and B are for information only.

This second edition cancels and replaces the first edition (ISO 15930-3:2002) which has been technically revised as

follows:

- The referenced version of the Adobe Portable Document Format has been changed from 1.3 to 1.4.

- The following features introduced in PDF 1.4 have been disallowed in PDF/X-3:2003: JBIG2, Transparency, and

Referenced PDF
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ISO/DIS 15930-3 (E)
Introduction

ISO 15930 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 minimising 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 form 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.

This part of ISO 15930 complements the other parts by defining a data format and its usage to permit the predictable

dissemination of a compound entity to one or more locations, as colour-managed data, CMYK data , and/or spot colour

data, in a form ready for final print reproduction, by transfer of a single file. This file must contain 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.

These goals are accomplished by defining a specific use of the publicly available Adobe Portable Document Format as

specified in Version 1.4. In order to achieve a level of exchange that avoids any ambiguity in interpretation of the file, it

identifies a limited set of PDF objects that may be used and adds restrictions to the use, or form of use, of those objects,

and/or keys within those objects.

Whereas this part of ISO 15930 specifies the exchange of complete material, with all elements present, there are

occasions where 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 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 other parts of ISO 15930. Other exchanges may be more appropriately

restricted to CMYK data only; such exchanges are addressed in Part 1 of this International Standard.

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.

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.

The PDF/X-1a conformance level of this version of this part of ISO 15930 is generally similar to that defined in the earlier

version of this International Standard, which was based on the Adobe Portable Document Format Version 1.3. This

version is based on the Adobe Portable Document Format Version 1.4.

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-3. These are defined in ISO 15930-3:2002 and ISO 15930-

3:2003. It is recommended that these be referred to as PDF/X-3:2002 and PDF/X-3:2003, respectively.

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ISO/DIS 15930-3(E)

An ongoing series of Application Notes [1] is maintained for the guidance of developers and users of the ISO PDF/X family

of International Standards. They are available from NPES The Association for Suppliers of Printing, Publishing and

Converting Technologies in the standards section at http://www.npes.org/standards/workroom.html.

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ISO/DIS 15930-3(E)
Graphic technology — Prepress digital data exchange —
Use of PDF —
Part 3:
Complete exchange suitable for colour-managed workflows
(PDF/X-3)
1 Scope

This part of ISO 15930 specifies the use of the Portable Document Format (PDF) for the dissemination of complete digital

data, in a single exchange, that contains all elements necessary for final print reproduction. Colour-managed, 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 15930-1:2003 Graphic technology — Prepress digital data exchange — Use of PDF — Part 1: Complete exchange

using CMYK data (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)

PDF reference : Adobe portable document format, Version 1.4, Adobe Systems Incorporated. — 3rd ed. (ISBN 0-201-

75839-3)
ICC.1:1998-09, File Format for Color Profiles, International Color Consortium
3 Terms and definitions

For the purposes of this part of this International Standard, 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

NOTE The bleed area includes area that may be printed but does not include printers’ marks of any kind.

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ISO/DIS 15930-3 (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

cyan-magenta-yellow-black used as a modifier of printing tone values, colours, process colorants, etc.

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 to 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
[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

3.12
ICC

International Color Consortium, an industry association formed to develop standardized mechanisms for colour

management
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ISO/DIS 15930-3(E)
3.13
ICC profile
set of colorimetric transforms prepared in accordance with ICC.1
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 bibliography items

[4] and [5].
3.15
non-print element

an element not intended for final print reproduction, including previews, preview images and all annotations other than

TrapNet or PrinterMarks
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
preview

visible placeholder representing at least the size and shape of the area to be replaced by the referenced object

NOTE A visible placeholder may be something as basic as a rectangle of the appropriate size containing no image content, or may

be a partial or complete representation of the intended content. See 3.19.
3.19
preview image

preview consisting of a raster image representing a compound entity at a resolution suitable for viewing on a computer

display
3.20
print element
an element intended for final print reproduction
3.21
printing tone value

data value corresponding to the relative area of a printing surface that is intended to transfer ink to the substrate being

printed
NOTE See 3.3, characterized printing condition
3.22
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.
3.23
reader
software application that is able to read and appropriately process files
3.24
spot colour

single colorant, identified by name, whose printing tone values are specified independently from colour values specified in

a colour coordinate system
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ISO/DIS 15930-3 (E)
3.24
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 colloquially referred to as chokes and spreads or grips. This is not the same as ink trapping.

3.25
writer
software application that is able to write files
4 Symbols and 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 purpose of this part of ISO 15930, references to the “PDF Reference" are to the PDF reference: Adobe portable

document format as identified in clause 2..
5 Conformance

This part of ISO 15930 defines the use of the PDF file format for the exchange of digital data representing a compound

entity.

A conforming PDF/X-3 file is a PDF file in which those features necessary for the exchange of a compound entity adhere

to this part of ISO 15930. A conforming file may also include other valid PDF features that do not affect final print

reproduction of the compound entity.

Neither the version number in the first line of a PDF file, nor the value of the Version key in the Catalog of a PDF file shall

be used in determining conformance with this part of ISO 15930.

A conforming writer is a software application that shall be able to write files conforming to the requirements of this part of

ISO 15930.

A conforming PDF/X-3 reader is a software application that shall be able to read and appropriately process all conforming

PDF/X-3 files as defined in this part of ISO 15930. A conforming PDF/X-3 reader shall also be able to read and process

all files conforming to all of the following that also conform to 6.16 of this part of ISO 15930:

• ISO 15930-3:2002 having a value of (PDF/X-3:2002) for the GTS_PDFXVersion key in the Info dictionary.

• ISO 15930-1:2001 having a value of (PDF/X-1:2001) for the GTS_PDFXVersion key and (PDF/X1a:2001) for the

GTS_PDFXConformance in the Info dictionary.

• ISO 15930-1:2003 having a value of (PDF/X-1a:2003) for the GTS_PDFXVersion key in the Info dictionary.

NOTE The ability to read files prepared in accordance with ISO 15930-3:2002, the predecessor to this part of ISO 15930, is

important to preserve upward compatibility. Further, because PDF/X-1a is technically a subset of PDF/X-3 it is important that a PDF/X-3

reader also recognise the PDF/X conformance keys that point to PDF/X-1a.

Although PDF reference permits compliance with earlier versions of PDF, features described in versions of the PDF

specification earlier than 1.4, but which are not described in PDF reference, should not be used in a conforming PDF/X-3

file. Such features may be ignored by a PDF/X-3 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.

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ISO/DIS 15930-3(E)

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 ISO 15930 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-3 file specifies Trapped=False, a conforming reader may use job ticket information

to determine details of how the file is to be trapped. If the file specifies Trapped=True, a conforming reader must 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-3 reader is permitted to ignore screening information in the PDF/X-3 file (see 6.9). A

conforming reader may use screening data from the PDF/X-3 file, from the job ticket, or from local system defaults.

6 Technical requirements
6.1 Data structure

A PDF/X-3 file consists of four sections: header, body, cross-reference table, and trailer. The body of a PDF/X-3 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

specific PDF features required by this part of ISO 15930 are summarized in Annex A and are defined in 6.2 to 6.17,

inclusive. These features shall be used as prescribed in the PDF reference and as further specified by this part of

ISO 15930.

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 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.

A PDF/X-3 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 shall be

contained in the body of a single PDF/X-3 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 For partial exchange of compound entities refer to ISO 15930-2 [3]. For complete exchange using CMYK data refer to

ISO 15930-1.
6.2 Colour
6.2.1 General

A PDF/X-3 file makes provision for exchanging data either as output device code values or as colorimetrically defined

data. Colorimetrically defined data shall be described either using an ICC profile in an ICCBased colour space or using an

equivalent mechanism, namely a CalGray, CalRGB or Lab colour space.

However, both types of data, if present in a PDF/X-3 file, shall be prepared 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.

Non-print elements may make use of any PDF colour space.
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ISO/DIS 15930-3 (E)
6.2.2 Identification of characterized printing condition

The intended output (i.e., the process colour model for the output device) condition for which data has been prepared is

identified by use of an OutputIntents array in the Catalog object. The OutputIntents array shall contain exactly one

OutputIntent dictionary in which the value of the S key is the name GTS_PDFX, henceforth referred to as the PDF/X

OutputIntent object. Additional OutputIntent dictionaries may be present; if so they shall use different values for the S key

and shall be ignored by a PDF/X-3 conforming reader.

The PDF/X OutputIntent object shall include the OutputConditionIdentifier key. Where the characterized printing

condition is a printing condition included in the registry of characterizations maintained by the ICC, as described in ICC.1,

the value of the OutputConditionIdentifier key should be exactly the same as the name used in the ICC registry.

If the OutputConditionIdentifier key does not match a characterization name in the ICC registry, a DestOutputProfile

key is required, and the OutputCondition key should be present.

If some or all colour data is not supplied in the process colour model of the characterized printing condition or the

OutputConditionIdentifier key does not match a characterization name in the ICC registry, a DestOutputProfile key is

required, and the OutputCondition key should be present..

NOTE 1 Even when not required, the DestOutputProfile key, and the OutputCondition key may be present.

If the value of the OutputConditionIdentifier key matches a characterization name in the ICC registry the RegistryName

key shall be present with the value (http://www.color.org). If it matches a characterization name in any other registry it is

strongly recommended that the RegistryName key be present, preferably with a value that provides a URL at which more

information regarding the registry may be obtained.

Where all colour data is supplied in the process colour model of the intended output condition, or in Separation,

DeviceN, Indexed or Pattern colour spaces that only make use of those process colours and/or spot colours, a

DestOutputProfile key is optional. If some or all colour data is not supplied in the process colour model of the intended

output condition or the OutputConditionIdentifier key does not match a characterization name in the ICC registry, a

DestOutputProfile key is required.

The profile that is the value of the DestOutputProfile key, if present, shall be an Output Device Profile (Device Class =

‘prtr’) as defined in ICC.1. If present in the DestOutputProfile stream object, the Alternate key shall be ignored by a

PDF/X-3 conforming reader.

The values of the profileDescriptionTag and charTargetTag, if present in the ICC profile, shall be ignored.

If the OutputCondition key is present its value should be a string describing the characterized printing condition in a form

that will be meaningful to a human operator at the site receiving the exchanged file.

NOTE 2 The PDF/X-1a:2001 and PDF/X-3:2002 conformance levels recommended the use of the Info key; while either maybe

used the OutputCondition key is now recommended.

NOTE 3 If some or all colour data is not supplied in the process colour model of the characterized printing condition, the intent is that

the profile that is the value of the DestOutputProfile key is to be used to transform the colour data provided into the process colour

model of the characterized printing condition.
6.2.3 DeviceCMYK

If a PDF/X-3 file includes colour data defined in DeviceCMYK and if the intended output device is not CMYK, a

DefaultCMYK colour space shall be included in the ColorSpace dictionary of the Resources dictionary of the root object of

the marking content. The DefaultCMYK colour space shall provide a colorimetric definition.

6.2.4 DeviceGray

If the characterized printing condition is CMYK, DeviceGray shall be taken as referring to the black separation of the

characterized printing condition.
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ISO/DIS 15930-3(E)

If a PDF/X-3 file includes colour data defined in DeviceGray, and if the intended output device is not CMYK or Gray, a

DefaultGray colour space shall be included in the ColorSpace dictionary of the Resources dictionary of the root object of

the marking content. The DefaultGray colour space shall provide a colorimetric definition

6.2.5 DeviceRGB

If a PDF/X-3 file includes colour data defined in DeviceRGB and if the intended output device is not RGB, a DefaultRGB

colour space shall be included in the ColorSpace dictionary
...