This may be a wild stab, but how is color management set up in your PDF .joboptions file? (In Distiller, choose "Default Settings", then Settings> Edit Adobe PDF Settings> Color tab> Color Management Policies). (May be different in your old Acrobat version) Some of those settings, as I recall, will change grayscale to color (such as "Tag Everything for Color Management). You probably want it set to "Leave Color Unchanged."
Mike Wickham On 12/11/2013 3:13 PM, Steve Rickaby wrote: > I know I'm using up all my tokens here, but... > > FrameMaker 7 -> .ps -> Distiller 6 -> PDF. > > Book contains many JPEGs. Book is to be printed in grayscale, so needs to > have no information in C, M and Y channels. JPEGs converted to 256-bit > grayscale, using the same workflow as I've used successfully many times > before. Developer of graphics editor (Thorsten Lemke, GraphicConverter) looks > at JPEG samples and swears they contain no color data (and he should know - > he's been developing GC for maybe 20 years). > > JPEGs inserted into FrameMaker and output as .ps, then distilled. In the PDF, > JPEG images have data in C, M and Y channels > > Anyone have any idea how this could happen? The last time it did, I had to > send pre-press files off to someone who had the latest Acrobat for pre-press > fixup. Lemke says FrameMaker is putting the color in! > > Setting the printer driver to output grayscale only does not fix this - > although it does map other color such as colored text to the K channel. > > What does fix it is converting the JPEGs to TIFFs. > > As my pal in Ohio is fond of saying, 'Go figure!' >
