PDF X/4 Question

[kdw75]

Am I correct in thinking that if I tell customers we want PDF X/4 files, we also need to rely on them choosing the correct output profile?

If theirs defaults to SWOP, and we run Gracol, aren't we diminishing color accuracy?

I would love to ask for X/4 files, but I can't rely on customers using anything other than the default X/4 settings.

 

[Stephen Marsh]

The same issue/problem exists for any flavour of PDF/X – they all require a specific/absolute output intent to be specified.

You could automate this process using say Enfocus PitStop Server. A hot folder could be setup with an action list to monitor for PDF/X-4 files using an output intent of GRACoL. If the PDF meets this criteria, it is moved to success folder. If the file fails, then it goes to an error folder.

It can of course get even deeper, you can make a second hot folder to monitor the error folder of the first hot folder – and then to automatically convert from SWOP to GRACoL using a devicelink profile and to change the output intent to GRACoL. I personally would not go this far as it may not be safe to assume that the file is actually in SWOP (a third hot folder would be used as an intermediate step to check for SWOP if this needed to be automated).

One idea of X-4 is that it is “safe” to supply the PDF with any tagged RGB/Lab/CMYK elements and they are all “fair game” for conversion (only really “safe” if using a properly configured devicelink profile, and then it still may not be all that “safe” depending on how you feel about the process). So if the output intent does not match, convert the CMYK content to a CMYK output intent that does match your output conditions.


Stephen Marsh

 

[toronar]

The same issue/problem exists for any flavour of PDF/X – they all require a specific/absolute output intent to be specified.

This is true even if the PDF is not a PDF/X.
If the customer only uses default settings, you will get SWOP-ish data. At least with PDF/X, you know you are getting SWOP.

 

[Stephen Marsh]

This is true even if the PDF is not a PDF/X.
If the customer only uses default settings, you will get SWOP-ish data. At least with PDF/X, you know you are getting SWOP.

If one is not converting colours, then one does not have to set a conversion profile, it is what it is.

What you get depends on your colour settings.

In my region, this would be Fogra 39 out of the box – not SWOP (and there are at least 3 versions of SWOP floating around in modern Adobe software).


Stephen Marsh

 

[Puch]

Moving to PDF/X-4 shows it's real advantages if you can persuade the clients NOT to separate images anymore. If they want to stick with CMYK data (for example, when their operators are trained to retouch in CMYK only), then the images must be properly tagged. This way APPE can do a perfect conversion for each of the objects on the page at the end, no matter what the output color space is. Actually, the the best quality can be achieved when converting directly to the printer's color space (when talking about a digital printer).

 

[mattbeals]

I am always in favor of PDF/X-4 if the right output intent can be specified. With X-4 you can convert to the OI or you can leave everything unconverted and specify what space to convert to (the OI).

But in this situation it may be best to ask everyone to use the "high quality" PDF setting since it will include all the ICC profiles and NOT convert to CMYK. This way you can do the conversion. Is it PDF/X-? No, but it does work well if you cannot ensure that the incoming PDF is PDF/X-4 compliant using your required OI.

 

[Glenn McDowall]

What do you guys do when the PDFX/4 output intent is incorrect? for example the images are tagged with mixed, SWOP and Fogra39 ICCs, the Output Intent is Fogra39 and you are going to printing litho on an uncoated Offset Stock?
Convert or reject?

 

[mattbeals]

Has the data already been converted to the OI, or does the OI specify the intended color space?

If it has already been converted then you would need to reject it or convert it.
If it has all the original color spaces for the objects but only had the OI specified (no conversion done yet), then change the OI.

Although to be most correct you'd probably want to reject it anyways since the OI is incorrect. If it hasn't been converted you at least have a chance to get it to the right color space even though it's not the most correct way to do it. That's one of the things that is so appealing with PDF/X-4 and high quality print settings. You don't have to convert the data like you do X-1a. You can simply specify your intentions by using the OI.

 

[toronar]

What do you guys do when the PDFX/4 output intent is incorrect? for example the images are tagged with mixed, SWOP and Fogra39 ICCs, the Output Intent is Fogra39 and you are going to printing litho on an uncoated Offset Stock?
Convert or reject?

We talk to the customer about this mismatch. Most of the times we get a blank stare (through the telephone) and then we convert to the real destination profile. Sometimes we get new data with the correct output intent. The overwhelming number of those "correct OI" are just the same data as before with the correct OI, so no conversion has taken place on the customer's side, just a re-tagging.