> only case where you'd need 300dpi - so I don't understand why this > option is there, without CMYK color. > AFAIK, the CMYK and support for other colour spaces is under development. The keyword is GEGL library. You are right, this is really something current versions lack a lot. But working with high DPI values is of course useful in the RGB colourspace too. In prepress, CMYK is needed in the last stages of workflow, but you can start with RGB images (and you have to start with them - no digital camera works in CMYK for example). So you can do your graphics in RGB but proper resolution in dpi (of course you can just compute sizes in pixels and not think about dpi at all, but it is little inconvenient) and then send it to a prepress studio. They will convert it to CMYK themselves, they do it a thousand times a day anyway.