Exporting from a Working CMYK to sGray keeping the spot colour of the folding

[miguelg78801750]

Hi guys,

I was wondering if you can give a hand with this, I've been playing around with different settings but I did't manage to fix it by myself.

So, I'm working in CMYK in Indesign CC 15.0.3. It's an instruction for use, so it will printed in litho/offset purely in gray scale but I added some folding lines as spot color pantone magenta in a different layer.

The problem I have is that as soon as I export the document (which is color proofed as Working CMYK) to sGray (PDF/X-1a:2001, Acrobat 4 PDF 1.3, Optimize dor Fast Web View, Export Layers: Visible & Printable Layers, Default Compression, All printer's marks addes less the bleed mark, including the document bleed settings, Color Conversion: Convert to Destination, Destination: sGray, Profile Inclusion Policy: Don't Include Profiles, Default Ink Manager and rest of it is default) it saves the content properly with the grayscale but converting the folding lines as well to grayscale. I would like to keep those ones as spot color. But the only way I found it was by exporting it with Color Conversion: Convert to Destionation (Preserve Numbers) and then Coated FOGRA39 (ISO 12647-2:2004), Profile Inclusion Policy: Don't Include Profiles and default Ink Manager.

Normally I just work as usual with Fogra39 CMYK saving it as PDF/X-1a:2001, Acrobat 4 PDF 1.3 and then the printers do the separations. But this time the printer asked me to send them a grayscale file so it will match better with the color proofed file the send me for the final OK before they send it to the machine. 

ANY IDEA ABOUT IT?

[DBLjan · Accepted solution]

Hi,

i couldnt mimic the actual pdf-process of yours, because my InDesign-Install hasnt the pdf-profile to grayscale at all, maybe a german client thing.

But, maybe this could be an approach:

Open Acrobat and take a look at Preflight. There is a default preflight profile to convert all colors to grayscale. If you duplicate that profile and change the settings (target: correct the desired grayscale-profile; next "tab" get rid of action 1 "all object not gray", and change the second from All Colors to All Colors without Spot) you can convert to grayscale and leave the spot.

[miguelg78801750]

Thank you mate, I was considering that option as well but I was more focused on being able to do it from Indesign but due to the lack of alternatives, I'll go through your suggestion.

[Luke Jennings3 · Accepted solution]

I think the best option would be to use black only type and convert the images to black only in their native format (Photoshop, Illustrator) where you have better control over the conversion, then export to a two color PDF (black + spot), keeping the folds on a separate layer. You can use the InDesign Separation Preview to confirm there is no CMY (window> Output> Separations Preview). Another option is to export to sGray without the fold lines, then place this PDF into a new InDesign file with the spot fold marks and export to a 2C PDF.

If this were to print on a digital press, you might want to leave out the crop marks, or use an Acrobat preflight profile to convert the Registration color to black only, the fold layer can be turned off in Acrobat.