Developments in Prepress Technology

62 Pages·0.338 MB·English

by  Pira International Ltd

Developments in Prepress Technology
Paul Lindström
Published by
Pira International Ltd
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© Copyright
Pira International Ltd 2006
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Contents
List of figures v AppleScript and Automator 24
Executive summary vii Visual Basic and Javascript 25
1
Automated impositioning 25
Presettings 25
Middleware and help tools 26
Developments in computer-to-plate
Introduction 1 production 27
Scope 1 Processless plates 27
Methodology 1 Violet vs thermal 28
Definitions 1
Developments in screening
2
technology 28
DI presses 29
Digital presses 30
JDF – the glue in a complex workflow 31
Quality assurance 7 4
Colour management 7
How it all begins 8
Characterisation of devices 11
Measure and calculate colour
Collaborative workflows 33
deviation 11
Digital asset management (DAM) 33
Proofing 12
Metadata 33
How to verify a proof 14
Versioning 35
How to verify a softproof viewed on a
Web interface and plug-ins 35
monitor 14
Colour management and image
Preflight 15
processing 36
Early preflight 16
Database support and portability 36
Server-based preflight 16
Digital Rights Management (DRM) 37
The X-files 17
Editorial systems 37
Adobe PDF Print Engine 18
Web publishing systems 38
Microsoft XML Paper Specification
Collaborative softproofing systems 39
(XPS) 18
Notification tools and web interface 39
Press control systems 19
Pixel streaming 40
Examples of press control systems 19
JDF 21 Preflight 40
3 Colour management 40
IT and security 41
JDF integration 41
Quark XPress7 41
Automation 23 Adobe Version Cue and WebDAV 42
Macros and Hot Folders 23 JDF and collaborative workflows 42
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Developments in Prepress Technology
Contents
5 Web to print, print on demand 49
JDF and databases 49
6
Database driven production 45
Management information systems
(MIS) 45 End-user trends 51
Cross media publishing 47 Publishing 51
Personalised print, print on demand 48 Packaging print production 52
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List of figures
2.1 Poor spectral distribution of office 3.1 An example of a fully automated DI
fluorescent light tubes 9 press 29
2.2 The spectral distribution of light from 3.2 The Kodak VersaMark digital
a light source conforming to D 10 press 30
50
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Executive summary
Prepress technology has entered a slightly less hectic phase after years of intense and
often dramatic changes in the execution of graphic arts production. This has generally
meant moving from a craft process, often involving many analogue components, to an
increasingly digitised and abstract production process. The internet has become the
natural communication channel for graphic arts production, and more and more software
and production systems rely on web browser technologies to interact with users.
Since page design and page creation is often the responsibility of the print buyer
and/or publisher, special attention has to be paid at the transfer points, where documents
move from one workflow stage or subprocess, to another. It is crucial to establish where
quality controls should be applied and who is responsible for them.
There are three main areas to be covered when establishing a highly efficient,
productive and profitable workflow: quality assurance, automation, and means to establish
network-based collaboration on projects.
In particular the following aspects are covered to provide examples of how to achieve
this:
 A key area of quality assurance is well-implemented and fully understood colour
management, both in regard to which measuring devices are needed, and which
software to use.
 Another important area of quality assurance is to establish preflight checks in the
workflow, and tightly integrate them into approval cycles.
 Automation can be done through extensive use of macros and scripting or custom-
tailored programming. Apple Script, Java Script and Visual Basic are examples of
suitable tools for this.
 Another important way to achieve a high degree of automation is to preset devices in
the workflow using the JDF (job definition format).
 Automated impositioning, presetting of CTP devices, printing presses and bindery
equipment should be a natural and integral part of modern print production.
 Many publishing scenarios call for teamwork based and collaborative types of
workflow. This in turn makes it necessary to introduce efficient databases in more
places in the workflow.
 In order to facilitate search and retrieval of documents, metadata has to be applied
to the files in the databases. Digital asset management (DAM) systems are examples
of where databases come into play, and rich metadata is essential.
 Introducing or expanding your present management information system (MIS) system
will help to facilitate efficient order management. Cost effective print production of
very short runs, down to one copy in personalised print, is another example where the
use of databases is essential.
 The predominant document formatting technology at the moment is XML, and it is
used throughout a modern publishing workflow. One application built on XML is JDF,
and it is a fair guess that the uptake of JDF will be substantial over the next two or
three years.
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1
Introduction
The days of staggeringly fast developments and changes in graphics arts production seem
to be over, at least for a while. The introduction of personal computers, Postscript and
soon after that, the arrival of the internet, had a dramatic impact on how publishing is
done today. However, today’s technology base has largely stabilised.
Scope Currently we are seeing a steady consolidation of how new technologies are used in
everyday work. In this study the objective is to identify the tools and means now available
to establish efficient workflows, signified by means for quality assurance and automation,
as well as network-based collaboration.
With an entirely digital workflow in place at most printers and publishers around
the world, the task now is to redefine how to ensure quality assurance, establish who is
responsible for what in the workflow and develop new print applications.
With new workflows come new ways to automate for efficiency. The internet has
brought additional ways to collaborate when proofing, to reduce errors and gain precious
time. Collaborative workflows also rely to a high degree on efficient and robust databases,
containing relevant and useful metadata.
Methodology There are few books entirely devoted to modern prepress workflows, so this technology
report is based on a wide selection of sources, ranging from what has been published in
both domestic and international trade magazines, observations from attending most of
the major trade shows as well as many special seminars, particularly in Europe and, of
course, visits to customer sites.
When possible, technologies and software have been tested for their specific uses,
be it colour management software and measuring devices, monitors, softproofing
systems, colour printers, DI presses, screening technologies or press control systems. When
statements are based on hands-on testing, this is indicated in the text. In addition to
documentation from vendors and distributors, both printers and publishers have been
interviewed in order to obtain different perspectives on trends and developments in the
market.
Definitions When describing modern prepress workflows and network-based production, it is impossible
not to use and introduce a lot of technical terminology, including a range of IT terms and
acronyms. Some of these are therefore listed below, to help in understanding the text.
AM screen
Amplitude modulated screen technology. The most commonly used system to generate
one-bit dot patterns on film or plate to create the appearance of greyscales in print.
Bitmaps
One-bit dot patterns created on paper, film or printing plates to generate the image to be
reproduced.
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Developments in Prepress Technology
Introduction
CIE
Commission Internationale de l’Eclairage. The organisation that created standardised ways
to describe and calculate colour conversions.
CIELab
The CIE colour space, a three-dimensional, approximately uniform colour space
produced by plotting L*, a*, b* values in rectangular coordinates, where L is luminance
(brightness), the a-axis are red to green colours and the b-axis are yellow to blue colours.
CIP4
Cooperation for the Integration of Processes in Prepress, Press, and Postpress. The
successor of CIP3, develops the Job Definition Format (JDF), the data standard for
electronic ‘job bags’.
CMYK – cyan, magenta, yellow, key (black)
The four subtractive process colours used in printing. Cyan, magenta and yellow are
the inverse of red, green and blue, and produce black when printed on white stock. But
the black produced by mixing C, M and Y is not pure (dark) enough for most printing
purposes, so black ink is included as the fourth colour. The black is referred to as K for key
– a shorthand for the printing term ‘key plate’ – because it is ‘key’ to producing accurate
darks.
Colour gamut
The range of colours in a scene or image, or that can be created on a particular output
device and/or medium.
CTP
Computer to plate – a technology to produce printing plates without the use of repro
films as an intermediate medium.
DAM system
Digital asset management system. A database for all the documents used in the
publishing process. By using indexes and rich metadata the documents can be fast and
easily retrieved by searching the database.
Delta E
A formula to calculate the difference between two colours, expressed in CIELab. The E is
generally understood to mean ‘error’, and is correctly written ∆E.
Desktop publishing
A phrase strongly associated with Paul Brainerd, founder of Aldus (later bought by
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