How to Produce Vector EPS with CMYK Color Using Free Software

This may not be the sexiest or even the most contemporaneous task to want to do in 2013, but recently I’ve had to deal with a vendor who requires vector EPS (PDF is not acceptable) and CMYK color for print items such as T-shirts and other swag. The problem with this deceivingly innocuous and charmingly antiquated specification is that it is was very difficult to do in FLOSS. I’ve tried what I thought was every permutation of exporting from every file format available in Inkscape and Scribus, and casting that output together with ghostscript tools in all the ways I could think of. The best results I could achieve was an EPS file with CMYK color that was rasterized, not vector. I was not the only one experiencing this issue. Some folks in the Libre Graphics community that I respect very much had the same problem. Ray suggested some things I could do to troubleshoot the issue that I hadn’t tried to try to coax the output I needed out of Inkscape and/or Scribus. Since I have 3 projects I’m dealing with that require interacting with this particular vendor, I’ve been more motivated than ever to find a libre way …