And this mistake was not visible to my eye when viewing the converted images on screen! They looked a shade darker, but nothing like they printed at the litho.
To fix this, should I go back to the original RGB images and leave conversion to CMYK until the output to PDF? Will this avoid the 'Pure Black' trap?
Indeed, how does one convert images to CMYK safely? Just turn off 'Preserve Pure Black' for each conversion, and back on again for the text?
I also notice in the Soft Proofing dialogue a box called 'Preserve CMYK numbers'. Should that be checked?
Any help with this would be gratefully appreciated!
Preserve pure black is not checked by default, if it's on turn it off. Map gray to CMYK black should be checked by default.
I would suggest setting rendering intent to perceptual instead of relative colorimetric. Make sure Photo-PAINTs color management matches Draw. I.E same profiles and rendering intent.
Let Draw embed the images, convert them via edit bitmap, taking them into Photo-PAINT to convert to CMYK, save the Draw file after importing each image, size the image and resample the resolution to what's required for output, then convert to CMYK in PP.
Use the default Press PDF settings in Draw you may want to convert fonts to curves in the PDF settings.
Just that other setting 'Preserve CMYK numbers' in Draw's Proof dialogue - should that be on or off?
Also, when I convert an image to CMYK in PP, should I embed the ICC Profile? I see that the profile gets embedded again in the PDF export. I presume it doesn't get embedded twice?
Unless you're using transparency or complex fountain fills just leave soft proofing off. If you feel you need it then make sure you're soft proofing the CMYK profile. The preserve CMYK numbers in the proof dialog can be off since we will export through the publish to PDF dialog. BEST if you design all in CMYK for print, if you don't RGB vectors will have a color shift. Also best to convert images to CMYK in the live file rather than in the publish to PDF dialog.
Make sure your CMYK profile in Photo-PAINT matches the one in Draw. Once you import an image into Draw AND SAVE the draw file the DRAW FILE color spaces are attached to that image. If it's and RGB image it will be the RGB profile same for CMYK or Grayscale. Import the image and hit ctrl s on the keyboard, then when you edit bitmap the RGB from your Draw file profile travels with the image and when you convert to CMYK in Photo-PAINT that profile will travel back to Draw.
Import the images, resize to fit the space, in the bitmap menu resample for output (print usually 300 dpi), edit bitmap and in PP color correct, send back to Draw and ctrl s.
Once you're happy under the file menu, publish to PDF, use the Corel default print setting for 99% of the world. You may want to set the fonts to curves if you're unsure if they embedded.
Thanks again, David. That's a great help!