I have designed a book with two colors: black and PMS 369C. I sent it to the printer just before going on holiday expecting no problems with it. But they returned to me saying that it has two definitions of black and they can't print it as two colors. They couldn't give me any more information than that however.
The book is made in indesign and has some vector images drawn in Illustrator. To get more nuances of the PMS color I mixed it with both white and black, I believe it's called overprint when mixing with black and I've only done that once before so it's quite possible that it is the cause of the problem. I must admit I have little understanding of color profiles but I think it's possible that the black I used in the Illustrator files is defined differently than the basic [black] swatch I used in InDesign. What is the correct way to define black for these kind of print jobs? And more importantly is there a simple way to remove one of the blacks in the PDF file and replace it with the other?
I'm attaching a screenshot from Acrobats output preview that might help.
The output preview reveals that there is one spot color black, but the process black is also used on other instances. Does it matter which one I use as long as I just use one of these blacks? Since I'm not using CMYK it seems counterintuitive to use 0,0,0,100 for black, but maybe it's alright?
I don't understand the ink manager but I saw that I can replace a spot color with an ink alias. If I set it to process black would it solve the problem? If it's that easy I don't understand why the printer would bother telling me to fix it rather than just doing it themselves?
But I suppose it isn't that easy. I should be able to fix it by editing each illustration in illustrator, it seems like deleting the K=100 swatch will revert any instance of that color back to 0,0,0, plus whatever tint percentage of K=100 was used. But there's probably a better way, either by fixing it directly in Acrobat or upon exporting from InDesign. Any suggestions?