I love to place original RGB files in Id and convert final PDF during export to CMYK at the last stage. (Export Adobe PDF dialog > Output > Color conversion). It works fine I think. But one thing is mystery for me.
Here is the export dialog:
The default option is set to Include Dest. Profile. It seemed prety logic to me and I did not understand why the local printer asked me to export data without the profile included. OK then, I did it as he asked me to. Small local printer I thought…
Now I exported print data to another, pretty big printing company and I tried to Include the profile. It resulted into this:
All the black text (pure K ink) has been converted into the each CMYK channel. Have a look at the separations preview in Acrobat (sorry for that interface, which is in Czech language):
I converted again, did not include profile and the result was right this time:
I am really confused. Why just including the profile do such brutal changes in pure black channel? Why si the Including Profile for than?
Thank you in advance!
It is only doing what you asked. You chose a profile and asked to convert to it.
Unless the data is
ALREADY using the same profile
it must be converted because you asked
This is why you should design with your final profile as your working profile.
Yes, it is a serious issue, but it is inherent in ICC profiles, which were designed in blissful ignorance of the problems of rich black, and which have been adopted everywhere.
Your dialog is showing that you are converting to Fogra and preserving numbers (inDesign swatches and colors export unchanged), so the conversion to 4-color blacks isn't happening when you export. But when you include a CMYK profile the output destination at the printer also has to be Fogra otherwise there will be a CMYK to CMYK conversion (4-color blacks) at output. If you include no profile the PDFs CMYK color is considered device CMYK and the values will output unchanged.
There would never be a reason to convert to anything other than the printers final destination CMYK, so if you export to CMYK you need to know the printer's output profile.