I have a PDF (v.1.7) made from Illustrator CS5. The PDF shows it has a mix of CMYK and RGB profiles in it. I thought Illustrator always converted to the working space or do I have that wrong? I tried reproducing this by setting my color settings to preserve image profile. Then I created a CMYK image in Illustrator. Placed a PSD that was made in RGB color space and finally did "Save a Copy" as a 1.7 PDF. Tried embedding the images tagged ICC profiles and without. My output PDFs were just CMYK. No RGB.
I'm trying to better understand how each Adobe application really handles color, especially when it comes to mixing color spaces. In my job I deal with lots of PDFs and have to make sure they print. When PDFs come with multiple color spaces this adds a whole new layer of complexity. I would like to know what it takes to do this to better understand Illustrators color management. Any ideas on how to reproduce a PDF with CMYK & RGB out of Illustrator would be great.
Also I've been looking online and have found some basics on how the programs handle color, but are there others you would recommend?
Illustrator does not convert RGB images to CMYK. If it did, you wouldn't have a mixed-up document. PDF is just a "Carrier" for your file, transporting it from A to B. So, eventhough it is a CMYK PDF, the RGB images probably got converted to CMYK in the PDF creation process. Therefore, there is no way to have a mixed color space PDF, either it is RGB or it is CMYK. I find Adobe's Print Publishing Guide a good source of accurate information.