The Portable Document Format (PDF) is the most common way we share our finished layouts. Anyone with Adobe’s free Acrobat Reader application can open a PDF and consume its content. And that’s just about everyone. Those who want to edit PDFs or add extra functionality to them can use Adobe Acrobat Pro, the powerful sibling to Reader. Adobe has been very effective at making PDF and these apps nearly ubiquitous. Maybe a little too effective: my training company often gets calls from prospective students who want to learn how to use “Adobe.” With some gentle questioning we confirm they’re trying to learn more about Adobe Acrobat.
The advantage of sharing a document as an Acrobat PDF rather than a Word or InDesign document is that PDFs retain the layout and text formatting of the authoring application without the recipient needing to have the author’s applications or fonts. When I receive Word docs from clients, I moan because just opening them will change them. Adobe built PDF to retain a faithful likeness to the original at the cost of making it hard to edit. But even that has become easier with the right software.
PDFs can be configured for a variety of print output devices or can be set up for entirely electronic consumption. Their file sizes can be very small (at the cost of image quality, usually) or large. There is no one PDF to rule them all; different eventualities often demand a differently configured PDF. Luckily, our recipients can often guide us and Adobe provides many presets to achieve common configurations.
Presets
InDesign can export (File > Export…) to many different file types. But when it’s PDF I need, I stop just short of that command and use File > Adobe PDF Presets, choosing the preset that most closely matches my needs. You’ll be prompted for a name and location to which to save the PDF. Then you still need to interact with another dialog box with many options. If you cancel at either stage, no PDF is made.
The Presets in square brackets (“[” and “]”) are built-in and cannot be changed. But if you do customize the settings in the Export Adobe PDF dialog, you’ll see the name of the preset with the word “modified” appended to it. You can save those customizations as your own preset to use later. And there are many things that you might choose to change! A private student once asked me to explain the pros and cons of every option. Twenty minutes later the student asked me to “stop, please.” Luckily, I covered the crucial things in the first five minutes, and few people other than prepress professionals need to know much more. Speaking of those special folks…
Better printing companies will often suggest which preset to choose or supply a custom preset they have made to suit their workflow. I recently consulted the website of one such printer and found wonderfully detailed advice for preparing files for output as well as a downloadable PDF preset. If your printer supplies such, you will need to “install” it. Some printers will instead show images of the various pages of the Export Adobe PDF dialog box, hoping you will match what they’re showing. Either way, you’ll need to “define” a PDF preset.
Choose File > Adobe PDF Presets > Define…. If you’re trying to follow instructions and screenshots, you’ll press the New… button. You will then navigate to a dialog box that is nearly identical to the one you use when actually exporting. We’ll get there in a moment.
If you’ve downloaded the preset, you’ll press the Load… button, then choose the file you downloaded (it will have an extension of “.joboptions”).
We will look at many of the details of this preset and some others as we go through the Export Adobe PDF dialog box.
General Options
When you use File > Adobe PDF Presets or go to File > Export… and select Adobe PDF (Print), you’ll be faced with the Export Adobe PDF dialog.
The first page of that dialog is called General. Some of its settings get altered if you change the preset, so I often leave General for last. There are important options found here. This is where you specify the range of pages to be exported (much easier to do if you have chosen Absolute page numbering in your General Preferences). You may choose for each InDesign page to be a PDF page, or you can have each PDF page be a “reader spread” by choosing to Export As Spreads. However, that setting and a number of others are not recommended for PDFs destined for print.
Viewing has a welcome set of options for whomever will open the PDF. For View, I invariably choose Fit Page so that no recipient is looking at only the top third of page one when they open the document. If my document is a series of single pages, I’ll choose Single Page or Single Page (Continuous) for Layout. If I have spreads (a.k.a., “facing pages”), one of the Two-Up options is more appropriate. There’s even provision for a singe title page followed by spreads (the options with Cover Page in the name). Always choose to View PDF after Exporting.
For PDFs destined for online viewing, there are many options to keep the file size low. One is the Preset called Smallest File Size, although you may find that the cost of “smallest” is too great, as image quality is often too low. More on that when we discuss Compression. Other options in General are the inclusion of modestly interactive elements, like any Hyperlinks you may have built. Bookmarks can be generated from an InDesign TOC, too. If you’ve built more elaborate interactivity involving buttons and transitions, then the export process should start with going to File > Export... and choosing Adobe PDF (Interactive) and its set of export options.
Create Tagged PDF is required to include tags for disabled accessibility. Create Acrobat Layers makes a PDF layer for each InDesign layer. You can choose which InDesign layers from the Export Layers menu. The All Layers choice means it, even including layers that have been made invisible or nonprinting!
Compression
The figure at left shows the settings for a book printer. But if you examine this section having chosen the Smallest File Size preset, you’ll see that all color images will experience Bicubic Downsampling to 100 ppi if their effective resolution is more than 150 ppi. See “Placing Images” (page 208) for more on that term. Grayscale images will be made 150 ppi. Those resolutions may indeed be appropriate for onscreen viewing. But the combination of Compression and Image Quality are JPEG and Low, respectively. After viewing the result, you’ll likely increase the quality to Medium or higher, yielding a larger but more palatable file.
The print-friendly settings shown use ZIP compression rather than JPEG, as file size is not so critical and ZIP is lossless compression, unlike JPEG which literally discards data! Since the compatibility is set to Acrobat 7, I could use JPEG 2000 (an option for Acrobat 6 and higher), which yields a better looking JPEG, but ZIP is quite literally best.
The Downsampling is also different. For this print preset, it’s set to 300 ppi for images whose effective resolution exceeds 450 ppi. At the bottom of the dialog are two checkboxes that will make a smaller file size while causing no harm: Compress Text and Line Art and Crop Image Data to Frames. Some users get apprehensive about the latter until they’re reminded that this is only cropping the images in the PDF, not the InDesign document.
Marks and Bleeds
Now we step off the page to what surrounds it. Arrayed beyond the bleed are the Crop Marks that determine where the paper will be cut. Some printers may also want more information like filename or date (Page Information).
Output
This ties into the management of color as discussed in chapter 5, “Color Management” (page 293). The key choice here is the Destination. If I’m creating a PDF to be viewed onscreen only, I’d likely choose sRGB, as that profile represents standard displays. For print, choose the profile indicated by your print shop—they may even supply one to install so you can choose it here. With a Destination profile chosen, specify the Color Conversion: Convert to Destination (Preserve Numbers).
With a CMYK Destination, this choice ensures that all RGB content is converted to the printer’s desired profile while maintaining any CMYK choices you may have made in InDesign.
It is possible that you will be asked to do No Color Conversion so that the printer may do it themselves with the most up-to-date profile. Profile Inclusion is also a decision of the print shop, as some of their software may not like to have that data embedded in the PDF.
The Ink Manager is a great last-minute rescuer. For example, let’s say you’ve built a brochure that includes logos from a dozen sponsors. Some of those logos use spot colors that require extra inks for which there is no budget. You don’t have to rebuild each logo to use only CMYK (process color). You merely have to check a box in the Ink Manager as you export your PDF: All Spots to Process.
Another option Ink Alias, which allows you to substitute one ink for another. One common use for that is swatches that use nearly the same spot color, but are actually different. In the example, an uncoated paper version of a spot color is being “aliased” to the coated version. That one, in turn, could be aliased to a third, maybe a process ink.
Advanced
Only a few options are of interest here for those with reasonably modern workflows.
Under Fonts, you have the option to reduce file size by embedding only the font data of the characters you used in InDesign (a Subset of them). This could be troublesome if a recipient needs to make a small text change with a character you didn’t embed. Thus, I choose 0% to force the full fonts to become part of PDFs, especially those for print.
Printers who have more current software to process PDFs can support transparency in the PDFs we send them. So if you’re asked to supply Acrobat 5 or newer Compatibility, artwork in your document that includes transparent effects like drop shadows or blend modes will be passed along in the PDF. If the Compatibility is Acrobat 4, InDesign uses a bunch of processing tricks to maintain the look of your artwork, but without transparency. This process is called flattening, and we choose a Flattener Preset that best fools the eye. We’re lucky that this is becoming less necessary all the time.
Security
With Document Open Password, you can encrypt the PDF so it cannot be opened without a password that you choose. So if you’re sharing a proprietary document, you can do so over less secure channels, comforted that an eavesdropper can’t open it.
The Permissions portion is less secure, but it attempts to prevent certain actions (printing or extracting content) unless a password is provided. However, one can open the PDF in some software that circumvents this.