Adobe’s PDF document format may have been with us for a while, but it’s only in recent years that it has become central to the printing industry. Digit looked at what the PDF revolution could mean for your creative workflow.
Adobe’s PDF file format has been around for over a decade now, but it’s only in the past three or four years that it’s started to become important in the printing and publishing industries. Printers will often ask their design customers to supply PDFs instead of EPS or native formats such as QuarkXPress. Larger newspaper and magazine publishers increasingly require advertisers to supply their ads as PDFs.
Most large magazine and newspaper publishers now produce PDFs to supply to printers, too. This has meant adapting their production workflows to generate, check, submit, and archive PDFs. But PDF workflows are relevant to all design and publishing operations, not just print.
A PDF workflow keeps everything you need for a document in a single file, including layout, text, graphics and font outline information. Downstream production processes and archive databases only need to be able to open PDFs, and don’t need access to a whole bunch of individual graphics programs and fonts.
The PDF creation process gives you control over image resolution, file compression, font handling, and colour management, and makes it easy to create several versions of the same document simultaneously. For example, you could create a different version for high-resolution print, medium-resolution proofing, low resolution publishing, and archiving.
There’s considerable multimedia support, so you can embed sound and movie files and set up hyperlinks between pages, or to other PDFs, or as URLs to the Web.
The Adobe Reader for PDF viewing and printing is free and widely distributed with all sorts of applications because PDF is used for manuals – if you’ve managed to escape it so far, you can download it from www.adobe.com.
Setting up a PDF workflow at the creative stage seems easy. You create your documents in your design program, then use one of a wide choice of built-in or third-party utilities to convert the whole thing to a PDF. Layout, fonts, pictures and colour are all embedded automatically.
The bad news is that creating reliably working PDFs can be a deceptively complex business. When it comes to professional printing, a PDF that gives the wrong result on a printing press can be very expensive.
The basic answer is to put a lot of effort into creating the correct settings for the PDF creation stage, making sure that everyone knows how to use them, and then to check everything with a pre-flight program before it’s sent to the customer or the printer.
Adobe Acrobat is the core software for creating, displaying, and editing PDF document files. Each pack contains Distiller, the vital utility that can create PDFs from any document. The main Acrobat application can open, display and print PDFs created elsewhere. It has very limited text-editing abilities.
It’s possible to create PDFs without Distiller – QuarkXPress 6, plus Creative Suite versions of InDesign, Illustrator, and Photoshop don’t need it, for instance, and Global Graphics PDF Creator is a lower-cost Distiller alternative. Mac OS X can convert any document to a basic PDF. However, it’s worth buying one copy of Acrobat, because it’s the basis for a lot of third-party PDF utilities that run as Acrobat extensions, such as preflighters.
Jumping through hoops
Last year’s Acrobat 6.0 was a major upgrade. It was the first to run completely in Mac OS X – there is a Windows version too. It introduced a new PDF 1.5 multi-layer file format, and supports the print-specific PDF/X-1a and PDF/X-3 formats.
Acrobat 6.0 Standard (£259 plus VAT) is for everyday document work, while Acrobat 6.0 Professional (£395 plus VAT) is for creating and outputting professional print work.
Professional adds a preflight module and the related ability to create and validate print-specific PDF/X files. Both versions include an advanced Print menu with a lot of professional controls.
If you’re working in a studio that needs multiple copies, the lower-cost Standard package would suit most of your workstations for general PDF-creation. A single Professional package would be a good investment to preflight and create PDF/X before final submission for print.
The PDF 1.5 format introduced in Acrobat 6.0 has improved support for the interactive object transparency of InDesign and Illustrator. It’s a mixed blessing, as only the latest PostScript Rips can output this. Fortunately, it adds improved tools for ‘flattening’ transparencies and converting late PDF versions to PDF 1.4 or 1.3.
What’s attracting designers and publishers is that PDF 1.5 can preserve multiple layers within the same document, and users can switch them on or off to view or print. For example, if you’re producing an ad campaign, brochure, or catalogue to distribute around Europe, you put text for each language on a separate layer and save the lot in a single PDF. This makes for easier distribution.
Multi-layer documents can be created in InDesign or Illustrator CS then exported to PDF 1.5. When you open this in Acrobat 6.0, it directs your attention to the layers tab that lets you switch any layer on or off for viewing and printing.
Distiller and Job Options
You can run Distiller as a standalone program to convert individual documents to PDFs, but more often you’ll run it in the background, accessed through the Print Menu where it appears in the list of printers as Adobe PDF. This writes a PostScript file that Distiller automatically converts to PDF and saves to disk.
Distiller settings can be confusing, and are the cause of nearly all PDF problems. See the PDF Checklist boxout for a few pointers.
The tabbed settings cover General (PDF version, alignments and overall resolution), Images (compression and resolution, including re-sampling options), Fonts (if and how they are embedded), Colour (ICC profiles including optional conversions), Advanced (PostScript and metadata), and PDF/X.
Distiller helps by providing Job Options – groups of settings tuned to a particular type of output. The Distiller 6.0 Job Options vary from Standard (medium compression,
with no colour or resolution changes), to High Quality (for print, low compression, 300dpi resolution, font embedding, no colour changes). There are higher-end job options too.
The Press option uses the same settings as Print except that font embedding is mandatory. The Smallest File Size option is mainly for Web or on-screen viewing, and uses 100dpi conversion with all colours as sRGB. Distiller 6.0 Professional adds PDF/X-1a – PDF/X-3 Options.
You can choose your own settings and save these as a new Job Option. This is saved in an individual small text file that can be given to other users and imported into their Distiller.
Professional printers often create Job Options tuned to their own processes and give these to customers, which helps cut down errors. If your printer hasn’t done this, ask them what settings they want, and create your own Job Options to suit.
Some pre-press developers have produced ‘helper’ programs for Acrobat and Distiller that printers can give to their customers. They are tuned to only allow the correct Job Options and settings for the target production process. They validate PDFs before submission, and embed JDF (Job Definition Format) production information that helps to automate the downstream workflows.
Enfocus runs a commercial Web site (www.certifiedpdf.net) where printers and publishers can place their specifications and Job Options for customers to download.
Global Graphics’ PDF Creator writes fully functional PDFs without Distiller. It’s available through the Print menu, though there’s a desktop drag-&-drop icon for conversion from EPS or PostScript. At £52 plus VAT, it’s significantly cheaper than buying the Acrobat Standard or Professional packages. PDF Creator 3.4 can create PDF 1.3 or 1.4, but not the latest PDF 1.5. It doesn’t support PDF/X directly.
Acrobat Distiller will work with watched hot folders, which are easy to set up and associate with a particular Job Option and security settings. You can create as many hotfolders as you like, with each one associated with a different Distiller profile.
You can write the completed PDFs to an output folder, which can then be used as the input folder for another process, such as a preflight checker or proof-printer queue.
Adobe doesn’t allow you to share watched Distiller folders across a network, as it makes a pricier server version of Distiller for this.
Some third-party automated job file transfer systems provide profiles, or even whole PDF creators, and check that they’re used before the files can be sent. These include Vio’s AdExpress, the Newspaper Society’s AdFast and Quickcut (all widely used by newspapers to receive ads) plus the commercial print oriented Global Graphics PDF Courier and Markzware FlightCheck Online.
Some document and graphics applications offer menus to create PDFs directly. You need to do a little research here, because some of these need Distiller to be present, as all they do is use a script to access it in the background.A handful of applications can create PDFs internally, with no need for Distiller.
The most common graphics program to access Distiller is QuarkXPress 4.x or 5.x for Mac OS 9 or Windows. However, with XPress 6, introduced last year, Quark supplies
a Global Graphics JAWS Rip that operates in the background to write PDFs directly. This can only create PDF 1.4 or 1.3, not the latest PDF 1.5.
Adobe provides extensions for Microsoft Office, to allow direct output of PDFs via Distiller from a toolbar button. Global Graphics does the same with PDF Creator.
The Adobe Creative Suite applications – InDesign, Illustrator, and Photoshop – can create PDFs directly through their Export menus, without using Distiller.
InDesign and Illustrator have an export menu for PDF output, with multi-level settings equivalent to Distiller’s. They offer Presets (similar to Distiller Job Options), with a mixture of Acrobat 6.0 settings (from PDF 1.3 to 1.5 and PDF/X), eBook, and Screen. You can save your own Presets but these can’t be transferred to other copies of InDesign or Illustrator. Neither can you import Distiller Job Option files.
According to a GATF (Graphic Arts Technology Foundation) survey in 2002, the most common errors in PDF files include fonts not embedding, wrong colour space, images missing, and overprint/trap issues. A PDF may look fine on screen, but the printed output can still be wrong.
Flight of fancy
Most professional PDF creators use preflight software that can check PDFs for errors and produce a report. The latest Acrobat 6.0 Professional (not Standard) has a preflight module. Its preflight report can be validated. This embeds it into the PDF where it can be read by the receiving end as proof that the file is good. The preflighter is comprehensive and includes a lot of pre-sets, but it’s hard to understand if you need to set up custom checks. There’s still a case to be made for third-party preflighters.
There are a few popular third-party preflight applications at the desktop level.
Enfocus InstantPDF is aimed at creatives, and costs £199 plus VAT. Enfocus PitStop Professional (£394 plus VAT) is for advanced users or pre-press studios, while Enfocus PitStop Server (£1,699 plus VAT) performs automatic checking with some auto-correction. Markzware’s FlightCheck Professional costs £299 plus VAT, and can check native documents such as QuarkXPress, Word, and InDesign.
At the top end are OneVision’s highly automated Asura (£13,500) and Solvero (£6,960). These are used by large publishers, studios, or pre-press houses. OneVision’s Speedflow is a lower-cost (£7,950), PDF-only model with checking, editing, and page imposition. It can be automated with Cockpit for £5,400.
The PDF/X factor
Some printers and publishers now ask for PDF/X files, which minimize confusion by specifying what can and can’t be inside a print-ready PDF. There are two versions, called PDF/X-1a (2001) and PDF/X-3. Each defines a ‘subset’ of an ordinary PDF 1.3 file that can only contain things that actually work in print, plus code flags that identify it as PDF/X. It can be output by any pre-press or printer Rip that can handle PDF 1.3 files.
Acrobat Distiller 6.0 Professional can create PDF/X-1a (essentially for CMYK plus spot colours), or PDF/X-3, which allows other colour spaces and ICC profiles. Distiller runs a preflight check and only writes the PDF/X file if it passes.
Acrobat 6.0 Professional can convert ordinary PDFs to PDF/X-1a or X/3 providing they pass its preflight. There are third-party options for converting PDFs to PDF/X too, such as Enfocus InstantPDF and PitStop Professional, OneVision’s Asura, Solvero, and Speedflow and the low-cost Apago PDF/X checker.
Before you make a PDF for professional print, run through this checklist. It could prevent expensive problems later on.
Fonts: Always embed fonts, and check in advance that your system can access the font files the document will need
Linked graphics: Be sure all links can be accessed from your computer, locally or across a network
Embedded graphics: Make sure all graphic files are linked instead of embedded in the native document
Resolution: Make sure pixel-based graphic files have enough resolution to print correctly
Scaled or rotated graphics in layouts: Try to avoid them. Scale or rotate graphics in the graphics application, and re-save
Colour mode: Convert all colours to CMYK and/or Spot colour for printing presses unless you are in a colour-managed workflow (ignore this if you’re using ink jet printers)
Number of colour plates (channels): Only use spot colours if you’re prepared to pay extra for printing. Most ink jet printers convert spots to CMYK automatically
Bleeds: Make sure that elements that overlap the edge of the page bleed correctly
Page size: Set the pages size(s) correctly for the paper
Overprinting objects: Check overprints and trapping before making the PDF
Adobe (Acrobat, Adobe Creative Suite): www.adobe.com
Agfa (ApogeeX Create): www.agfa.com
Apago (PDF/X Checker): www.apago.com
Callas (pdfInspektor): www.callas.de
CIP4 (JDF): www.cip4.org
Creo (Synapse Create): www.creo.com
Global Graphics (JAWS PDF Creator, Editor, Courier): www.globalgraphics.com
Enfocus (InstantPDF, PitStop Professional, PitStop Server): www.enfocus.com
Markzware (FlightCheck Professional, Online): www.markzware.com
OneVision (Asura, Solvero, Speedflow): www.onevision.com
PPA (pass4press): www.pass4press.com
Vio (AdExpress): www.adexpress.co.uk