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Transparency Compliance with PDF/x-1a

Forum|Forum|8 years ago
August 11, 2017
5 replies
21707 views

Hello Folks,

I've been designing a book layout for a friend that will be printed using POD. Ingram Lightning Source through DrivethroughRPG is the company that is doing the printing. I have created a very intricate design that works for his RPG book that is 474 pages long. There is a lot of art and texture. It's a lovely book, and I'm very happy with it.

The problem is that I'm not very knowledgeable about printing in general. The specs provided mentioned nothing about transparency being an issue. Later, I discovered that transparency is a no-no in PDF/X-1a:2001, which is what the printer wants. However, the PDF file is LOADED with opacity shifts and art with transparent backgrounds. (By the way, InDesign gave me no warning about this when I exported to PDF/X-1a:2001!) The art needs to be faded slightly into the subtle textured background. To accommodate their no-transparency rule, I'd have to do some major overhauling on the file after weeks of work. I can see a route to still getting the effects I want without using transparency in InDesign/PDF, but it involves creating a page background for every page that has art with transparency, with the art flattened into the page background ahead of time in Photoshop rather than in InDesign. As you can imagine, this would get tedious very quickly! It would means using unique backgrounds for the art pages instead of master pages. Major headache!

So, my question is, are there any workarounds for this kind of thing? I have a message in to the printer for help also, but I thought I'd inquire here.

Michael

This topic has been closed for replies.

Correct answer Dov Isaacs

To summarize the responses here ...

For reliable PDF print publishing workflows, PDF/X-4 is strongly recommended as the PDF subset standard to use. PDF/X-4 supports live transparency and ICC color management.

On the other hand, PDF/X-1a forces all transparency in your original content to be “flattened” into opaque objects and all color to be converted into DeviceCMYK. The flattening process often results in quality degradation with flattening artifacts including stitching lines. Conversion to DeviceCMYK assumes that whoever directs you to convert to CMYK actually tells you which CMYK!!! US Web Coated SWOP? FOGRA? Which? If this isn't specified by the print service provider, expect color “issues” when printing.

Ironically, virtually all RIPs / DFEs (Digital Front Ends) sold over the last ten years support live transparency, color management, and PDF/X-4. It is the fear and ignorance of many print service providers that causes them to either require or request PDF/X-1a. Luddites!! In fact, RIPs / DFEs that support PDF/X-4 will yield superior output with PDF/X-4 as opposed to PDF/X-1a generated from the same original content that had live transparency. The PDF file will generally be smaller and RIP faster as well!

All that having been said, if you are not able or willing to find a print service provider who has entered the 21st Century, if you carefully prepare a PDF/X-1a file, you may get acceptable results if and only if the print service provider provides you with the information as to (1) what the CMYK color space they use is and (2) what the resolution is that they print at. Flattening should be done at a resolution close as possible to that of the rendering device (much of flattening prematurely converts text and/or vector objects into raster images if one or more of the overlapping objects in transparency are raster images).

And optimize for quick web view is totally and utterly irrelevant for printing in any way! (Tends to confirm ignorance of whoever is providing these specifications!)

Good luck!

- Dov

jeroenduller

Participant

According to the standard, PDF / X-1a 2001 version 1.3 uses PDF which flattens transparency. And PDF / x-1a 2003 is applied to version 1.4 PDF, which allows transparency.
However, in InDesign when you select PDF / X-1a 2003 the PDF version is set to 1.3 and not 1.4. I see no difference between the 2001 and 2003 standard. Even with PDF / X-3 version 1.3 is applied and thus transparency is flattened. Only PDF / X-4 maintains transparency.

T

Test Screen Name

Legend

That's actually an out and out contradiction in someone's instructions. PDF/X-1a must be PDF 1.3 or older. There is no middle ground, it just can't be.

rob day

Community Expert

that will be printed using POD. Ingram Lightning Source

If you don't have it, here is Ingram Spark's most recent file creation guide:

https://www.ingramspark.com/hubfs/downloads/file-creation-guide.pdf

See page 11 for text color requirements—although it's not in the guide, they spec the default US Web Coated SWOP v2 to be used as the document CMYK profile on their FAQ page.

CMYK was resolved along with ink coverage specs (240%)

Their 240% requirement seems to be referring to rich black swatch builds and not total ink. When you convert images, US Web Coated SWOP allows 300% total ink.

The backgrounds were a layered Illustrator file placed into the master pages. They included text, which did not get flattened in the final PDF. Now that I think about it, this is making me wonder if the export is not working correctly.

You can use AcrobatPro's preflight to check for transparency. Tools>Print Production>Preflight>PDF/Compliance. Choose a profile and click Analyze.

Output Preview panel will also tell you if there is transparency on the page:

Dov IsaacsCorrect answer

Legend

To summarize the responses here ...

For reliable PDF print publishing workflows, PDF/X-4 is strongly recommended as the PDF subset standard to use. PDF/X-4 supports live transparency and ICC color management.

On the other hand, PDF/X-1a forces all transparency in your original content to be “flattened” into opaque objects and all color to be converted into DeviceCMYK. The flattening process often results in quality degradation with flattening artifacts including stitching lines. Conversion to DeviceCMYK assumes that whoever directs you to convert to CMYK actually tells you which CMYK!!! US Web Coated SWOP? FOGRA? Which? If this isn't specified by the print service provider, expect color “issues” when printing.

Ironically, virtually all RIPs / DFEs (Digital Front Ends) sold over the last ten years support live transparency, color management, and PDF/X-4. It is the fear and ignorance of many print service providers that causes them to either require or request PDF/X-1a. Luddites!! In fact, RIPs / DFEs that support PDF/X-4 will yield superior output with PDF/X-4 as opposed to PDF/X-1a generated from the same original content that had live transparency. The PDF file will generally be smaller and RIP faster as well!

All that having been said, if you are not able or willing to find a print service provider who has entered the 21st Century, if you carefully prepare a PDF/X-1a file, you may get acceptable results if and only if the print service provider provides you with the information as to (1) what the CMYK color space they use is and (2) what the resolution is that they print at. Flattening should be done at a resolution close as possible to that of the rendering device (much of flattening prematurely converts text and/or vector objects into raster images if one or more of the overlapping objects in transparency are raster images).

And optimize for quick web view is totally and utterly irrelevant for printing in any way! (Tends to confirm ignorance of whoever is providing these specifications!)

Good luck!

- Dov

- Dov Isaacs, former Adobe Principal Scientist (April 30, 1990 - May 30, 2021)

P

positive_build0D4CAuthor

Inspiring

Incidentally, I'm pretty sure that some of the graphics are not being flattened, by the way. In the PDF, I can search on text used in the background (that is faded down so light that it's very subtle). The backgrounds were a layered Illustrator file placed into the master pages. They included text, which did not get flattened in the final PDF. Now that I think about it, this is making me wonder if the export is not working correctly.

Michael

—Michael

T

Test Screen Name

Legend

That would be a serious bug if flattening wasn't done. But your test doesn't prove anything. Especially if the opacity shift is constant; that can just be done using lighter text. Why not use a function that checks if there is live transparency? Flattening is done millions of times an hour and works. For instance every time you print from Acrobat.

BobLevine

Community Expert

This is really something you should have asked BEFORE starting. PDF/X1-a is nothing short of archaic. It is more than 15 years old and there’s no place for it in a modern workflow. Many printers that ask for it are capable of handling X-4 files

I have no idea what “opacity shifts” means. By definition, everything gets flattened in X1a as well as converted to CMYK.

That out of the way, if the file is properly created and exported, it SHOULD print properly.

P

positive_build0D4CAuthor

Inspiring

Thanks for the quick reply, Bob!

>>This is really something you should have asked BEFORE starting. PDF/X1-a is nothing short of archaic. It is more than 15 years old and there’s no place for it in a modern workflow.<<
Tell me about it. But, then again, I did ask ahead of time. The instructions provided said absolutely nothing about it. My error was in not being familiar with PDF/x-1a. However, in my defense, it took some major searching to even find out that transparency wasn't allowed. I only found out by reading that later PDF formats added transparency as a feature.

>>I have no idea what “opacity shifts” means<<
I mean setting the opacity of objects within InDesign to something other than 100%. It's under Effects. I set opacity to 85% for all text, and some artwork was set to as little as 40% in order to get the faded effect I wanted.

>>By definition, everything gets flattened in X1a as well as converted to CMYK. That out of the way, if the file is properly created and exported, it SHOULD print properly.<<

I agree, which is why I'm confused and posted here. I exported the file from InDesign precisely as the printer indicated. There were no Preflight errors or other indications that something went wrong. I viewed PDF extensively before sending to the printer, and everything looks exactly the way I wanted it to. If it isn't the export going off somehow, then I suspect they are objecting to the artwork with a transparent background (placed as unflattened PSDs). If it's that, that would be the easiest thing to fix.

Thanks for the reply. Let me know if you have any other ideas.

Michael

—Michael

BobLevine

Community Expert

If you actually chose X/1-a there is no transparency in the file.

Did you change anything from that preset at all?

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