Indesign export pdf noirs 100% sortent en noirs quadri

[Sol_sha]

Bonjour,
Je me permets de vous solliciter sur un problème tout récent que je rencontre avec Indesign et l'export pdf. J'ai trouvé des sujets similaires mais aucune solution ne fonctionne chez moi.  
Jusqu'ici, quand je créais un fichier Indesign avec le noir Indesign, ce dernier sortait soit en noir quadri 100% (sans pourcentage de CMJ) soit en noir ton direct (vérification faite avec l'outil prépresse d'Adobe reader).  
J'ai créé récemment deux nouveaux fichiers et cette fois, je rencontre un problème : mes noirs 100% sortent avec un pourcentage de CMJ en prépresse. Dans un cas, j'ai une impression quadri de prévue, donc l'imprimeur me dit qu'il va se débrouiller mais je dois reconnaître que ça ne me rassure pas : je crains que les textes et parties de l'illu qui sont en noir sortent mal. Dans l'autre cas, c'est encore plus problématique : je fais une impression avec 2 pantones + noir, donc pas de CMJ prévus. Si je fais un export pdf sans conversion de couleur, là j'ai bien un noir 100% sans CMJ mais l'illu sort plus terne. L'imprimeur me dit de faire ça et d'ajouter un fond pantone à l'illu pour la réhausser, mais là aussi, faire une sortie sans conversion de couleur et avec une couche de pantone en plus ne me rassure pas.
Je n'ai changé aucun paramètre dans Indesign, la surimpression du noir est bien cochée et je suis en Document ou Espace de travail CMJN (et l'un ou l'autre ne change rien). Il y a quelque chose qui m'échappe....
Sauriez-vous me donner un conseil/coup de main pour résoudre ce problème ?  
Je vous remercie par avance de toute l'aide que vous pourriez m'apporter pour comprendre ce qui se passe.

Bonne journée,
Sol

[rob day]

Hi @Sol_sha , Can you show a screen capture of the Output tab of the Export preset you are using? Also, if you check the black values using InDesign’s Separation Preview do they read as 4-color?

[Sol_sha]

Hello Rob, thank you for your answer. Here is a screen capture of the usual settings I use for the export. About the Separation Preview, no, it reads the black at 100% black, without CMJ. The problem exists also with an entirely black maquette (only text, interior of a book), in prepresse, it's a CMJN black, which is annoying because my printing is exclusively black. Thanks a lot for your help!

[Sol_sha]

I add that in the "ink manager" (I don't know the term in english, Gestionnaire d'encres in french) of the Output tab, I have indeed CMJ? But I don't have it in Separation Preview. I don't get it!

[Rene Andritsch]

Check this article for the Separation Window: https://helpx.adobe.com/fr/indesign/using/preparing-pdfs-service-providers.html

[Sol_sha]

I'm sorry, i didn't understand what can I check in this article. In the Separation Window, I have indeed a quadri black but it's at 100%, without CMJ even if it linked to the CMJN profil... Maybe I miss something? Thanks again!

[rob day]

Your Export Output setting is including the Destination CMYK output profile. If you include the profile and the prepress department outputs to a different CMYK profile there would be a conversion to a 4-color black.

Try Don’t Include Profiles or use one of the PDF/X presets—the PDF/X standard does not embed the document CMYK profile with document CMYK colors, and includes an Output Intent profile instead. That make it less likely there will be profile conflicts at output:

[Sol_sha]

Thanks a lot! It works on my pantone document: I have my two pantones and a black 100% without CMJ. I did the same with my CMJN document, same settings as you indicate, but here again: CMJ black. But for this document, in my Separation Window, I have indeed a black with CMJ informations.  However, I selected the Indesign black which indicates N = 100 and 0 for CMJ. Do you know how can I modify that?

Again, thanks a lot, you bring me a big help!

[Sol_sha]

I add that on my CMJN document, when I deselect the superimposition of the black on Edition > Preferences > Aspect of the black (I translate my french titles), I have a 100% black in my Separation Window for the text (not for the image but maybe it contains some CMJ informations and it's ok). But deselect the superimposition doesn't seem right to me... What do you think?

[Sol_sha]

Me again. New info: my text is full black when there is no colored background. So is the background the problem? However, I have other documents with colored backgrounds and there is no problem, the text is full black. I tried to create a new file and do all the document again and as soon as I add a colored background (whatever the color is), the text passes in CMJN. Sorry for these repeat questions!

[rob day]

Yes, I use a black plates on an offset press, exactly, without CMJ because -> pantone for the colors

So you are paying the printer to add extra black plates to the press? Why not just use the Process Black plate for all of the black elements?

my text is full black when there is no colored background. So is the background the problem?

The [Black] swatch by default Overprints, so yes if it is printing over another color, the background CMY values would be added. But you want that to happen otherwise the small black text will have to trap to the background color.

You want this:

Not this:

[Sol_sha]

Hum... I have to say I don't know if the printer uses extra black plates or the process black plate actually. I have to ask him (and I'll do). What does that change to my file? Can I simplify the process?

And yes, you're right. I will let my CMJN document like this so. I was wondering because on my previous documents, the Separation Window indicates a 100% black on the text without CMJ (but maybe it's not right finally), but on my last print, there is indeed overprint and the cover is ok.

Again, a big thank you for your help and your attention!

[rob day]

It would be unusual to run multiple black plates—it would be considerably more expensive. Years ago for highend printing you might run the text and image black separation on separate plates, but I’m guessing no one does that anymore.

Generally speaking you always want small (less than 20pt) black text to overprint.

[Sol_sha]

Ok, thank you. My text is indeed small except for the overprinted book's title, but I don't see how change that (I need a title a little bigger in bookshops :)). For the plates, ok I understand better, I don't think my printer uses extra black plates given the prices he makes but I'll ask him to check that.

I understand much better some Indesign features now (probably simple but as autodidact... you know)! Thank you 🙂

[rob day]

Offset inks are somewhat transparent, so for large areas of black you might want to create a process black swatch with CMY, otherwise large areas of black can appear as dark gray. Here I’ve made a Process (not Spot) Swatch named Rich Black with CMYK values of 55|40|40|100 and applied that to the black background:

[Sol_sha]

Ok, great! I'll see if it's necessary for my title (it's not that big). On my previous books, I overprinted the black on pantone color or on CMJN for the last book, and it was ok, not gray so I think we're finally good! But I keep in mind this option for the rich black (thanks for giving the values) if needeed and I'll test it. Tanks for the advices!

[rob day]

I have my two pantones and a black 100% without CMJ

What is the purpose of the Spot color blacks, are you running extra black plates on an offset press?

Generally speaking when a Process CMYK black-only color (0|0|0|100) converts to 4-color, there has to be a profile conflict somewhere in the printflow. It could happen on a PDF Export if you set an Output> Destination profile that conflicts with the document’s Assigned CMYK Profile (Edit>Assign Profiles...).

It could also happen at the print end if you include the document CMYK profile in the Output tab’s Profile Inclusion Policy, and the printer outputs to a different profile. If you don’t want your CMYK color values changing at output then there is no need to include the CMYK profile.

[Sol_sha]

Thank you for your response. Yes, I use a black plates on an offset press, exactly, without CMJ because -> pantone for the colors. For my pantone document, it's okay, the solution you offered works so a big thank you. I now try to resolve the problem on another document quoted in my first message, with extra informations above. The black of the text is 100% and 0% CMJ on the choice of color but in Separation Window, there is indeed CMJ (so oviously they will be here in the pdf). When I have no colored background, it's ok, but as soon as I add this background, the black becomes CMJ in Separation Window. Before, on other documents, my blacks stay black even if there is a colored background. There is something I don't understand here. Thanks again for the time you give me!

[Rene Andritsch]

You state that it is a recent problem. Have you updated InDesign? Please also tell us which version you are working in.

[Sol_sha]

Hello Rene, thank you for your response. Yes, the problem is recent but as the updates are automatic, I can't date it exactly from a new version. I use the 19.4 version. Thanks for your help!