Illustrator and pdf/x1-A separations anomalies?

[rich_orielly@adobeforums.com]

Has anyone else experienced separations from Illustartor CS2 Mac separating differently to a postscript printer (Canon CLC1120, EFI RIP) than from a pdf/x1-a made via writing a ps file from the same ai file and then Distilling (v7) with pdf/x1-a settings and printing to same printer? Specifically my noted anomalies are overprints in Illustartor knocking out in the pdf and today I had a Process Black in Illustartor separate as a 4 color black in pdf. I'm doing the same thing in both apps but I'm getting discrepancies @ the backend. Illustrator separates files as I've intended. pdf doesn't seem to do that. It makes me a bit nervous about my vendors who might take my Illustrator art and run it through a pdf workflow. Any thoughts or tribal knowledge are appreciated! Thanks!

[peter kleinheider]

Dear rich

I would have to look at the files. I can only think of 2 issue. The obect in the PDF is defined as DeviceGray which is set to overprint. By definiton, DeviceGray can ONLY overprint DeviceN. Meaning: if the object is placed over a CMYK Object, it will always knock out the CMYK elements.

The other thing idea is: In your distiller settings you have not activated the option for the illustrator overprint mode (has nothing to do with Illustrator by the way).
If the Text is defined in 100% Black defined as DeviceCMYK, is set to overprint, but has no illustrator overprint mode set (technically speaking: OPM = 0) then you have the same situation as described in case 1.

best regards

Peter