Portable Document Format (PDF ) workflows promise a world where prepress troubleshooting is minimal and where jobs enter a printing plant and move effortlessly through the digital workflow. Right now use of PDF files (sometimes called Acrobat files) can theoretically fulfill that promise, but most customers in the printing industry don’t have the knowledge or training to prepare usable PDF files.
A perfect PDF file includes all the fonts, all the graphics, and has everything needed to print the file properly. Most prepress operators believe a bad PDF is useless or worse than a bad application file because a PDF file can be difficult to edit. An application allows you to extensively edit, relink new images, or add fonts. These tasks are more difficult with a PDF.
“PDF is a like double-edged sword. Sometimes it’s a friend and sometimes an enemy,” said Sue Byers of Gannett Offset/Boston, printers of USA Today as well as other papers. “When it is created correctly it can be a great time saver, but when it is created badly (missing fonts, images saved in RGB, etc) it leaves you helpless and scratching your head.”
The most common complaints are missing fonts and low resolution graphics. In addition, the lack of bleed, loss of spot colors and wrong color space are also common issues. Many of these issues are related to the client’s lack of knowledge about how to create a usable PDF. Basically, in order to create a PDF that can be used for prepress, the customer needs to know many of the things that prepress operators know before creating the PDF. In some cases, customers and their printer may not want to take the extra effort to learn this process, but in many cases the benefits are worth it.
PDF is the future, and while PDF workflows may be bumpy right now, the future of this industry will most likely see in increase in the role of PDF workflows. Acrobat and the PDF tools included are very powerful and can do more than most people realize.
Distiller is basically a powerful Raster Image Processor (RIP). In theory, with a copy of Distiller, an inexpensive Postscript Level 3 RIP such as Harlequin, and a PDF Trapping solution such as Heidelberg Supertrap, users can create a system with the same functions as high-end production RIP. In addition with a copy of Distiller and Acrobat a user can create a high resolution PDF and drive almost any inkjet proofer directly via the windows print driver. Interesting ideas, although at this early point the support issues make it an unlikely choice for most users. The main point though is that PDF workflows can provide powerful tools and give you the power of a high-end production system for much less money.
In the future, these high-end capabilities will become available for smaller printers who may not have the resources presently for high-end RIPs and productions systems right now.
With the current state of PDF workflows being great, when the file is prepared correctly, help is needed. This is where PDF X comes in (the X stands for “exchange”). The PDF file format is extremely flexible and can handle many different types of media, ranging from print, to audio and video and even databases. This flexibility is great for many purposes, but for print it causes problems, such as allowing people to use RGB graphics in PDF files as well as many other issues.
The PDF X standard was created to eliminate common prepress problems with PDF files. (All the fonts and images are embedded in a PDF X file, and color is limited to a supported color space such as CMYK or spot, trap is tagged as on or off, and the file is created for the correct printing condition such as SWOP, etc.)
PDF limits the type of PDF settings and configurations that can be used and restricts the properties of these PDF settings. If both the client and the printer use the same settings then the result is no surprises and a file that can be used by both.
The PDF can have anything in it, including things that cause the PDF file to be usable from the view or prepress production. A PDF X file limits the scope of the PDF and what is in it and makes it something that can be used in prepress production without worrying whether the file was prepared correctly. It is simply a PDF file with restrictions.
It can get a little confusing because at this writing there are at least three different variations of PDF X. The variations are PDF X-1, PDF X-2 and PDF X-3. The PDF X-1 standard was originally published in 1999, and updated in 2001. This is the original exchange standard and is based on PDF 1.3.
The standard defines two specifications: PDF X-1 and PDF X-1A. PDF X-1 is the original standard. PDF X-1A is similar to PDF X-1 except that it prohibits OPI (image linking and replacement) and makes sure the images are included in the PDF file.
PDF X-3 is based on PDF X-1A, and is based on PDF 1.4. With PDF X-3, color-managed data may be included. (In PDF X-1A all colors are forced to CMYK, with spot colors being optional, and no color management is allowed.) In a PDF X-3 file, there may be data that is color-managed using embedded ICC profiles. PDF X-3 is expected to be approved this spring. RGB data is allowed as long as it is in a device-independent space. This may be helpful for certain workflows, but allows too many color “unknowns” for most commercial printing operations.
PDF X-2 is under development. PDF X-2 is based on PDF X-3 and allows color-managed data to be included, as well as OPI and non-embedded fonts, as well as tools to allow identifying these links to fonts and images.
What is the difference?
PDF X-1 and PDF X-1A pretty much lock down the file, making sure that all the fonts, images, and color space are restricted to a narrow set of choices that tend to work well in printing environments. PDF X-3 and especially PDF X-2 provide more flexibility with PDF X-3 locking the file but allowing more options with regard to color management, and PDF X-2 allowing more options with regard to color as well as image and fonts linking and other custom workflow specifications. PDF X-1 will be most common when you want to lock the file down and make it bulletproof. PDF X-3 and PDF X-2 will be used for customized workflows in which the PDF creator and the printer are working closely together and want to take advantage of some of the benefits offered by having a more flexible but complex workflow.
Keep in mind that part of the value of PDF is to eliminate some of these options so that you know what you are dealing with and can be sure of having success with it.
So how does PDF X work? How do you make a PDF X file? While it is possible to make PDF X files directly from distiller there are some tools that make the process much easier. Tools such as Apago PDF /X Checkup, Enfocus Pitstop, Callas PDF inspector2, allow users to preflight and correct common problems and certify a file as PDF X compliant.
For example, a typical PDF X workflow a user may make a PDF file using the Distiller (or another PDF creation program such as Apogee Create or Harlequin Jaws.) and then run it through one of the above programs to preflight and fix the file so that it is PDF X compliant.
These utilities will be able to give a list of objects that do not conform to PDF X and in many cases will be able to fix the problems and then save the file as a PDF X file. These tools are essential for a PDF workflow, both for the creator so that they can certify that they have produced a valid PDF X file, and for the printer so that they can change or adjust the PDF X file if needed.
For example the tools above allow the user to add missing fonts, convert color spaces, and other valuable functions needed to make a non-PDF X file into a PDF X file.
You may be thinking, “Aha! Here we are again; back at the preflight issues,” which is basically the idea that if customers can’t preflight their own files now before sending them, what is going to make them suddenly able to preflight PDF files? This is an important issue.
Obviously if they are unable to be thorough enough to give us a set of application files that include all the image and fonts – despite the fact that very good preflight programs such as Flightcheck exist — what makes us think that these same customers will be able to make PDF X files even though good PDF X preflight tools also exist?
The answer lies with the success stories. In some market segments such as commercial printing, PDF X may not be a reality until developers such as Quark and Adobe put a “Create PDF X” option in the file menu, or make a Distiller setting to do this. In many environments such as cold web and repeat commercial applications, however, printers have found that if they take the time to set up the customer with a set of Distiller job options, and train them on how to make the PDF, they can get good PDFs which they can use without having to even open an application.
It works best when there is something to gain for both the customer and the printer. In this environment it is worth taking the time to teach the customer and configure their copy of Distiller. This is what works today and now. In the future it will become even easier to make PDF X files.
Imagine PDF X as a standard that can easily be created or exported out of most common applications. Picture a prepress environment where you no longer have large staffs dedicated just to fixing and prepping customer files. Perhaps a job comes in already certified, is imposed, and sent directly to a direct imaging press where the prepress operator and the pressman are the same.
Where do we go from here? If you are in an industry such as publication or news, PDF is here and if your customers are not using then you can probably benefit from PDF X. If you are a commercial printer with repeat jobs you may also be able to benefit. Otherwise keep watching and waiting and some time in the next year or two PDF may begin to make sense for you.