Inkjet colour calibration?

[Ian Goldby]

The gimp-print and cups-gimp-print drivers for my Epson Stylus 740 do a pretty amazingly good job of photographic prints, but whether its the 3rd party inks I'm using or the paper, the colour balance is not great, especially for neutral tones. In particular, a particular image that is almost a silhouette prints with a distinct green cast in the darkest regions (unless I use black ink only of course).

I want to do a proper calibration of my printer. I found cups-calibrate. I didn't get all that far with it - it doesn't seem to deal with interactions between the inks and removing colour casts, and I wasn't convinced it was working properly anyway. The calibration it came up with was crazy - far too light. I couldn't find any documentation for it either.

What I really want is something that will print out a set of swatches that covers the entire gamut of which the printer is capable - e.g. a 6x6x6x6 CMYK matrix. I would then scan this back in on my flatbed scanner, adjusting the scanner settings so that the image on the screen is close to the printout (this should be easier than print calibrating as both the scanner and screen work in RGB). The net result would be "If you want that RGB colour, then this is the amount of C, M, Y, and K ink you need to lay down".

What have other people done?