When printing with one color black on press cmyk? or grayscale?

[Samuel_Daneliuk@adobeforums.com]

Hey Guys

I was proofing some pdfs that im sending off to press for a one color job (black) and noticed that when using the seperations preview for some of the ads when I turn off the black plate there is nothing left and on other ads the cym make up some of the image...if this job is only one color on press should that be happening? or should I convert all the ads to grayscale instead of cmyk?

Thanks in Advance
Samuel

[Peggy_Coquet@adobeforums.com]

I had a piece of (grey-scale appearing) CMYK art in an ad on a black-only
page, and my customer was billed for 3 additional plates (about US$240) when
the printer's automated system generated seps for that page. So I convert
all art to the appropriate color space.

YMMV
Peggy

[Larry_Grohman@adobeforums.com]

It would appear that the objects that are showing data in the CMY channels
are indeed CMYK. Finding such inconsistencies is exactly what the
separations preview function is intended for.

They will separate to four plates in most RIPs, unless the printer changes
them to K only. Whether or not you get charged for this prepress service
will depend on the printer's policy.

Larry

[theano_mouratides@adobeforums.com]

Our grayscale InDesign files fail Pitstop preflight everytime because of the printers marks. We have to blow up the generated separations huge and inspect them closely to ensure there is no actual CMY in the files. Or sometimes we turn off the printers marks and preflight the resulting PDF. As long as it is printers marks only, we don't get charged for (and the printer doesn't make) the additional plates.

Theano