Introduced by Adobe Systems in 1993, and now available as an open standard, the PDF (portable document format) has become the mainstay of document interchange. In our business it fills two key roles: to facilitate the transfer of layouts from the customer to the shop; and to give printing vendors an efficient way to handle large complicated layouts internally. Whether you know it or not these files are everywhere, and it's helpful to know a little about them.
At the simplest level, PDFs allow you to view or print a file created on someone else's computer, and have it render correctly. This amazing feat can be accomplished even if you don't have the same software used to create the file, because all the data needed is contained, (in a very efficient way), in the PDF itself. You don't need to be running the same kind of machine or the same operating system. Windows, MAC, UNIX...don't matter.
Again, at the simplest level, the viewing of the file is done by Acrobat Reader, which is available on countless websites including this one...you can get it for free here. The viewing capability is also embedded in web browsers such as Internet Explorer, Google Chrome, Firefox, etc. No one should ever have to say "I can't open that file...it's a PDF". If you do, call me and we'll get it fixed.
Creating a PDF is not possible using Acrobat Reader, however, so you'll need the full Acrobat software, or have PDF generating capability built into another application you use. This step is not a "save as" function, where you select PDF as the file type. Rather, PDFs are created by a process called "distilling" which translates the file into postscript language; it's just like what your computer does to process a page for your laser or ink jet, but with a specialized driver which creates the PDF file.
This is why creating a PDF is usually done by "printing" the document, but selecting "Adobe PDF Writer" as the printer. At this point you have access to "Properties" which, like any printer dialogue box, presents you with a bewildering set of choices, and we'll discuss a few of the settings you may need to tweak. The other options are to use an "Export" function or other single-button choice built into the application used to create the document in the first place.
In the print shop, PDFs serve two critical functions: to allow us to take in files from otherwise postscript-unfriendly programs such as Word, Publisher, and even PowerPoint; and to give us a way of processing all page files efficiently. Most modern shops now have a PDF-based workflow, so if you can load the driver specific to their system you may be able to save some money at the pre-flight stage. At some shops this step is mandatory. Be sure to ask your rep.
"The problems we encounter, however, deserve some attention, and usually concern bleeds, fonts, and color."
Allowance for bleeds, may not be automatic. If the trim size of your document is 8.5 x 11 and includes bleeds, the final size of the PDF must be slightly larger. This close-up shows the correct extra allowance for bleeds, with the interior set of tick marks for the final trim from the oversize sheet. This problem is the number one reason files get bounced back for re-work, and shows up almost every day at our shop. Please stick with it until the file is correct, or ask for help if you can't solve the problem yourself.Click image to see full size.
Fonts not embedded is another problem. One of the critical factors of a PDF is that it contains all the information required for faithful reproduction on someone else's machine. For this to be true all the relevant fonts from your system need to be included, but, unfortunately, the default setting sometimes excludes some or all typefaces. The result is that the missing fonts will be scrounged from those available on the other person's computer, with a possible mis-match and unpredictable results. This is bad...REALLY BAD, because resulting errors may not show up at first glance even if they exist throughout the document.
The best generic choice for settings, to embed fonts and for other reasons, is "Press Quality". After creating the PDF, open it in Acrobat and look at the "fonts" tab in File>Properties. Any font properly embedded will be listed with "embedded subset" following the name. If that term is missing, the situation needs to be resolved.
Black which isn't really black. This is the last area of concern, and is mentioned because you can use a neat tool in Acrobat to check for it. Files born in an RGB color space often end up with black which is not a single, solid color, but a blend of CMYK when distilled. If you're trying to use the PDF as a bridge from Word, for instance, that CMYK black won't print properly since the black value in the mix is a percentage, not solid. It'll look gray.
Acrobat will allow you to check the output colors with one of the Print Production tools called "Output Preview" which is very informative. You can click "off" the colors in the file one by one and see the result onscreen. If you uncheck the black ink box, you will hope to see all the black copy disappear. If it doesn't, that's a red flag. There is another tool to fix this, but that's for my printing geeks only. Otherwise, it's probably sufficient to mention the potential problem to the printer, who may have other ways to cope with it.
The PDF is the closest thing we have to a "Rosetta Stone" in print production. Although it isn't foolproof, and can be frustrated particularly by those applications which need its' help the most, it solves an immense number of problems. From a customer point of view, this means the ability to get your job into the print shop quickly and accurately, whether your running Creative Suite 4 or Word '95.
I know a designer who named her dog "Adobe". With the constant flow of good ideas from this company, and their real world usefulness, all I can say is... "Good Dog"!!!
Hugh Butler
Your friend in the printing business
