PDF export that identifies B&W and Colour pages (CMYK?)

My printshop operator said something about exporting a PDF where the printer prints B&W pages BW and pages with images (ie colour) in Colour- this can save me large chunks of cash now and in the future as they really gouge you for colour at printshops.

I am taking a leap and assuming it is something to do with CMYK vs RGB as K is definite black as opposed to darkblue or however RGB approximates black.

Does anyone know if LibreOffice can export this way, it seems a real boon for a desktop publisher to have, especially in the academic environment where I am constantly printing out wads and wads of papers and drafts etc, with a few colour coded tables here and there, and yes I know i can separate them, but its really quite a timewaster.

My default settings PDF did not differentiate and I cannot find any specific option in LibreOffice.
I would also be fine using a third party PDF-CMYK tool if anyone knows.

Libreoffice 4,1,4,2
Windows 7

I am searching for the same solution! (didn’t find it so far). However, if you have Adobe Acrobat installed - when printing to PDF, you can choose conversion types like Press or High quality (just click Preferences or Properties next to Adobe PDF printer in Printing dialog) and it will export it as CMYK (where black K = 100% and others CMY = 0% each).

Maybe the option in writer for print text in black, can help: Menu/Tools/Options/LibreOffice writer

I use pdf creator, it has the option to select the color type for pdf output.

I think this has nothing to do with CMYK? Print text in black is probably RGB (0,0,0) and not CMYK (0,0,0,100). The problem when exporing to PDF is that text looks like black, but it is not black to CMYK printers :slight_smile:

This is not a job for an office suite, but rather a post-processing tool, such as ghostscript (gs) or pdftk that can manipulate PDF files. It is possible to export greyscale pages to one PDF and all colour pages to another PDF. The colour PDF can then, if required, be converted from RGB to CMYK, although any decent print shop can do this anyway. Example ghostscript command:

$ gs -o cmyk.pdf -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress -sProcessColorModel=DeviceCMYK -sColorConversionStrategy=CMYK -sColorConversionStrategyForImages=CMYK rgb.pdf

well i had a good play with both python and ghostscript but after three hours ended up with exactly nothing but handfuls of hair :stuck_out_tongue:

I receive this error: “ColorConversionStrategy is incompatible to ProcessColorModel”. Unrecoverable error: rangecheck in .putdeviceprops ???

@Ljiljan, the command works under GhostScript v9.05, although it is always possible a newer version has changed the paramaters. Does /DeviceCMYK instead of simply DeviceCMYK for the Process Color Model make any difference?

It does work now :slight_smile: thanks

As an alternative to Adobe pdf Writer I am using the pdf955 suite. This allows to select black&white or color under Properties > Paper/Quality


There is a free version with commercials or you can get a license for little money.