R2000 - any linux users?

[racing_green]

It's a bit more complicated. From gutenprint manual about Color Model:
"-RGB Color Send RGB (red/green/blue) data to Gutenprint. This is the normal choice when printing in color. While most color printers are actually CMYK devices, it is normally best to send RGB color to Gutenprint to allow Gutenprint to most effectively determine the CMYK output
-CMYK Send CMYK (cyan/magenta/yellow/black) data to Gutenprint. This is useful if you have generated CMYK output based on your own knowledge of the printer or a CMYK output profile, otherwise it will yield inferior results"

Same manual on ink Type:
"Some inks or paper/ink combinations produce color shifts when the light inks are used. If your chosen combination produces unacceptable color shifts or color casts, you may prefer to use the Four Color Standard option, which will generally yield more consistent color at the expense of “grainier” output."

 

[racing_green]

Overcast sky, white balance corrected. My print shows green tint and strong blue. Is that something that can be corrected with colour profile or I should keep exploring the settings and gutenprint manual?

 

[racing_green]

[..]I never had any luck with the the Gutenprint/CUPS drivers - the dithering algorithm just didn't seem to be up to it, similar to what you're getting.[..]

Just in case someone has the same problem in the future: gutenprint has 9 dithering algorithms and some of my problems were probably related to using defaults values. EvenTone or Hyblid EvenTone are the best for photography. From the documentation:
- EvenTone This relatively new algorithm yields excellent smoothness in all tones (light, midtone, and shadow), but is considerably slower than most of the other algorithms. It is somewhat prone to artifacts, including “tearing”, at sharp boundaries. This algorithm is well-suited for printing photographs, but is not as suitable for printing solid-tone graphics.

- Hybrid EvenTone This algorithm combines Even Tone and Ordered dithering to yield smooth results with fewer artifacts than Even Tone dithering, but is even slower than standard Even Tone. It uses the fixed pattern of Ordered dithering to break up the artifacts of Even Tone dithering. The result is not quite as smooth as pure Even Tone, but the reduction of artifacts makes this an excellent choice for photographs or photographs mixed with other graphics.

I'm still tasting, but I should have some interesting results soon.

 

[ninj]

Thanks - I tried some test prints with Eventone and it's certainly an improvement (good enough for casual viewing), but still more visible dithering and loss of fine detail compared with Turboprint. Possibly because, unlike with the R2000, Gutenprint's Canon Pixma IP8700 driver is marked 'experimental'. It doesn't have an option for resolutions higher than 600dpi, and the options include control over light cyan and light magenta (which my printer doesn't have) but no grey ink control (which it does), so I'm not even sure it's using all 5 dye inks. I could probably improve the general appearance further by creating an ICC profile, but I think I'll stick with Turboprint for my printer for the time being as results are consistently excellent. I would prefer to use an open-source driver though.

 

[racing_green]

[..]
- heavy banding (*) on blue (also green, but that's probably from blue) - middle of the test strip i the darkest point!

I tried RGB and CMYK in print window with mixed results. CMYK gives less banding, but producess green tint.

[..]

(*) I don't think I used the word correctly. I wanted to say that blue gradient going from full saturation to white has a glitch in the middle. View attachment 10316

For future reference: the problem was related to gimp colour profile conversion from Adobe RGB 1998 to GIMP built-in sRGB, not to cups/gutenprint/colour model/dithering method/colour correction.

P.S. Please do not assess the quality of the print. I'm waiting for propylene glycol