Comparing the standards

There are any number of settings that you could use when you're creating a PDF but when you're preparing PDFs for print, well, you might say that X marks the spot. What are all those PDF X flavors? They're not all the same so let's explore. First of all, the X stands for exchange. The motivation behind creating these standards was to set up specifications that would ensure that a PDF would print reliably under certain workflows. That is, that the file could be blindly exchanged with a vendor and be successful.

So, let's start with PDF/X-1a. It's the oldest spec, it's compatible with Acrobat 4.0 and I realize that seems kind of ancient now but it's still really handy. It allows you to have CMYK, grayscale and spot content but you can't have RGB or L*a*b content. Fonts have to be embedded and subset. Trim and bleed boxes have to be defined in the file and that's an internal definition and it's something that the original application, such as Illustrator or InDesign actually is responsible for.

There's no live transparency, it has to all be flattened, and layers aren't supported. PDF/X-3, wait did I skip X-2? Well, no there really never was a published X-2 so we jump from X-1 to X-3. So, as time goes by and workflows get a little bit more sophisticated and more capable, these settings evolve, these standards become more modern so X-3 can do some stuff that X-1 wouldn't let you do. It's still sort of way back compatible with Acrobat 4.0.

It allows CMYK and grayscale, but it also allows RGB and L*a*b and, of course, spot. And then the rest of it is pretty much the same. Trim and bleed boxes defined in the file, fonts embedded in subset, no live transparency. Everything has be flattened and, once again, layers aren't supported. Now, as things get more modern, workflows get more sophisticated, things start to loosen up a bit. PDF/X-4 is compatible with Acrobat 7.0. It allows CMYK, grayscale, RGB, L*a*b, spot, and everything you can throw at it.

Trim and bleed boxes, fonts embedded in subset. Ah, but here you go, live transparency. Now, why would that matter? Does it matter if you have to flatten transparency? Well, not having to flatten it may mean a little bit faster processing. It may mean a smaller PDF. It's just really a more modern approach to things. And then, layers are supported and that might be sort of handy if you're doing versioning, such as language versioning. But these aren't the only standards, there are other standards that are not related to the graphic arts industry but if you're curious, PDF/A is intended for archiving.

It's compatible with Acrobat 5.0 and it's intention is for the digital preservation of electronic documents. And so, as you might expect, it's fairly strict. Embedded fonts, no transparency, and in truth the long-term success of this as a digital archiving mechanism is really going to depend on the the capabilities of future viewer applications. If a hundred years down the line, there isn't a viewer application that knows what to do with a file like this, well, then we sort of lost our way. But the intention here is to create a nailed-down format that's going to carry forward into the future and be readable.

PDF/E, the "E" is for engineering. It's compatible with Acrobat 7.0 and Acrobat 6.0 and above support layers so this supports layers as well as 3D content which is kind of interesting and support for animation. So, you can imagine for engineering drawings out of CAD programs, you might be able to rotate a view of the object in your PDF and this is really a pretty neat feature. So, you want to tell as good a story as you can about something like an industrial design. PDF/VT, the "V" is for variable, the "T" is for transactional, variable and transactional data.

Compatible with Acrobat 7.0, supports wide range of colors, spaces, and transparency. And the idea behind this is for, well, all those letters that you get in the mail that are addressed to you personally and maybe have a picture of your car it, this is a way to support that kind of variable data. Transactional data, such as you get on your phone bill every month. And this can only be used in CIP4, that may be a foreign term to you, CIP4 job ticket formats. CIP4 is an industry-wide set of controls and control environments for pre-press and press.

So, I hope this overview has made you a little bit more comfortable with the alphabet soup of standards and maybe you're starting to have an idea of which approach makes sense for your particular workflow.