Placed PDF over-inking on Export

[CJC Williams]

I'm putting together a magazine with multiple adverts placed in to the pages.  

On Exporting the PDF to send to the printer, one of the placed adverts is showing as seriously over-inking when i preflight it.

The advert was created by an agency and is a PDF with Adobe RGB as the colourspace

The output profile for the indesign to PDF tells it to "Convert to Destination (Preserve Numbers)", destination is "Coated FOGRA39" (which has a 330% inking limit).

Everything else in the mag (a mix of RGB, CMYK and a plethora of colour spaces) all preocesses and ends up under teh 330% ink limit as I expected, but this one advert comes out the other side with 380%+ inking, and I can't work out why.

Can anyone help with where to look now?

[sunny.sunny]

Did you try to convert colors in this PDF file using Acrobat?

https://helpx.adobe.com/acrobat/using/color-conversion-ink-management-acrobat.html

[CJC Williams]

Yes. I tried converting colours (as an experiment) to Adobe RGB and letting Indesign do the colour conversion to FOGRA39 when i export the whole document to PDF for the printer. That didn't work.

I then tried "Convert to Output Intent" with the profile set as FOGRA 39. That didn't work either. On the Output preview (simulation profile set to FOGRA39) it is still showing large areas of 380% inking

[sunny.sunny]

OK, and did you try to change the ink limit on images using Photoshop? This is what I always do when I get closed PDF files from customers. 

First what you have to have to do is to check what files are "overinked". Tools --> Print Production --> Output Preview. In "Total Area Coverage" enter your max ink limit. You will see highlighted areas on images. All you have to do is to edit images in Photoshop. 

[Willi Adelberger]

You should never open any PDF from Customers in Photoshop. Fonts and vectors will be rasterised and the color profile is destroyed as a PDF can contain several different color profiles.

What you should do, give the client a list of criterias at hand what they have to deliver to you. My recommendation for placing is:

• PDF/X-4, with RGB images, CMYK vectors and text. Avoid any other PDF for placing in InDesign, no PDF/X-1a or X-3 or any Ghostwriter or Quartz PDF. (Even if you print to X-1a or X-3, never place such PDFs into InDesign. It is a no go.)
• Minimum image resolution.
• Output intend color profile you are working with.
• Final Size
• Bleed for any direction
• With or without marks.
• No fonts converted to outlines, but all fonts embedded, which is part of the X-stndards.
• No locked file. Editing should be alowed, but you should not edit it.
• No use of EPS inside InDesign.
• If spot colors, define which are allowed, or require process colors only.

If the client has this information, it is his responsibilityif something fails.

[sunny.sunny]

I'm writing about opening PDFs in Acrobat and then using Edit Image (with Photoshop) option in Acrobat.

[Willi Adelberger]

Why do you want to open PDFs on your side anyway? It is not your task. Give the client the specification he needs to create correct PDFs. You should require RGB images in that PDF. That is what PDF/X-3 and X-4 are made for. I do not recommend X-3.

[sunny.sunny]

You are absolutely right! But... it is much easier (i.e. faster) for me to edit one or two images than explaining all technical recommendations. 

[Willi Adelberger]

It is not explaining the client technical things. Hand the clients descriptions what you want and supply your clients with prests .joboption files to export correct PDFs.

[sunny.sunny]

In a perfect world, your solution would be great. But 3/4 of people who are working for big companies (and are ordering in my company) have very little knowledge of how to use basic functions in Photoshop or InDesign. Try to imagine their face when they receive .joboption 🙂 I'm way too lazy (or not good enough in teaching) to waste time on explaining. Kind regards!

[rob day]

You should require RGB images in that PDF. That is what PDF/X-3 and X-4 are made for.

Hi Willy, it is possible to build a document with all RGB color using certain blending modes and exceed the Output Intent profile’s total ink limit when the transparency is live. Here’s my example with all of the color as RGB exported to the default PDF/X-4 preset (No Color Conversion) in AcrobatPro:

I can get the correct ink limit by flattening the page’s transparency using Acrobat Pro’s Flattener Preview

[J E L]

Interesting, I have an off-topic question for you, Willi. Why do you suggest using RGB images instead of CMYK images in the first place? I always specify converting individual image files (to clarify, I mean the actual JPG or TIF image files themselves and not a PDF that includes text and images) to CMYK in Photoshop before inserting them into any InDesign layout for PDF export print applications. I’ve never had any issues using that method. Thanks!

[rob day]

It’s because InDesign uses the same color management as Photoshop so the same conversion to CMYK can happen on export or even in the RIP when the correct CMYK profile is known. There isn’t a problem with making the conversion in Photoshop, you just have to know what profile to use and it’s a less efficient workflow. Placing RGB has a potential gamut problem, but InDesign’s Overprint Preview shows RGB in gamut.

[J E L]

Exactly, I often design photo books and ask photographers to send me images already converted to TIF 300 dpi CMYK with the printer-specified color space, typically NA General Purpose 2 (advanced mode) with US Web Coated (SWOP) v2. Thanks!

[rob day]

with US Web Coated (SWOP) v2. Thanks!

That works as long as the final press profile is in fact SWOP.

Placing RGB is more flexible because you might have to change printers, and if the new printer requires Coated GRACol, the conversion of all the images from RGB to GRACol (or any other CMYK space) can happen on a PDF export from InDesign by setting the Destination profile to Coated GRACol.

[Willi Adelberger]

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@J E L  schrieb:

Interesting, I have an off-topic question for you, Willi. Why do you suggest using RGB images instead of CMYK images in the first place? I always specify converting individual image files (to clarify, I mean the actual JPG or TIF image files themselves and not a PDF that includes text and images) to CMYK in Photoshop before inserting them into any InDesign layout for PDF export print applications. I’ve never had any issues using that method. Thanks!

---

InDesign, Photoshop and Illustrator use the very same Adobe Color Engine. It is installed only once. If you have the same settings you will get exactly the same result if you convert from RGB to CMYK in Photoshop or if you do it with the PDF export from InDesign, also when you print from RGB Photoshop to a CMYK printer.

You have with RGB images the higher flexiblity to convert to different output profiles, or if you create a PDF/X-4 you can print with RGB images in the PDF to a CMYK printer which uses the APPE2 (Adobe PDF Print Engine).

You can use the InDesign file for exporting to PDF output like PDF interactive, PDF/UA, PDF for Web, EPUB, etc.

In Photoshop you can turn on the CMYK Print Proof Preview for RGB files too. 

You can do the same for spot colors, so you can have a RGB file with a spot chanel and you can choose to convert with colormanagement both, RGB and Spot according the color management to process colors.

Read also this:

https://creativepro.com/import-rgb-images-indesign-convert-cmyk-export/

[J E L]

Makes sense. I use Bridge to sync my printer-specified color space across all applications. But I still feel compelled to have individual image files already in CMYK before I place them in InDesign! Old habits die hard... Thank you!

[rob day]

Can you share the problem PDF?

[CJC Williams]

Here it is. 

[rob day · Accepted solution]

Its because of the Multiply blending mode blending with RGB black:

I was able to fix the total ink problem by setting the blend space to Adobe RGB and flattening:

[CJC Williams]

Thanks Rob, That method does bring everything back within inking limits. I'll have to make a note of it as it is something that doesn't happen very often but is a bit of a bugbear when it crops up. Cheers

[rob day]

Certain Transparency Blending Effects applied over dark values can cause total ink problem—modes that darken like Color Burn, Multiply, Darken.

Here I’m getting 375% with Coated FOGRA39 as the document CMYK assignment because I’m multiplying a dark CMYK color over and area of RGB black:

If I set the Blend space to RGB I get the FOGRA ink limit, but then there is the risk of black text converting to 4-color.

Yes. I tried converting colours (as an experiment) to Adobe RGB and letting Indesign do the colour conversion to FOGRA39 when i export the whole document to PDF for the printer. That didn't work.

Try flattening the live transparency and blending modes PDF before converting to AdobeRGB

[rob day]

Just to get back on topic, in this case the total ink problem isn’t being caused by a color conversion. The PDF @CJC Williams posted has areas of total ink approaching 400% which indicates the problem is with the Multiply blending mode used in the PDF.

A PDF/X-4 export or exports with live transparency with certain blending modes combined with dark colors can cause total ink problems.