Date: Wed, 16 Apr 2008 09:24:57 +0900
From: "Gernot Hassenpflug" <aikishugyo@...>
A second follow-up message: it seems that if I select highest
resolution (1440 x 720 high quality) with best color and best print
quality, plus 6-color photo inks, and set the printing type to
photograph, then I can get a good color demarcation and printing
from the Epson PM-670C for photos---no more dotting.
I have a problem with the colors though: my photo is of cherry
blossoms against a green and gray background. The entire image is
however tinted yellow/green, and I would like to calibrate the
printer: there appear to be more than 20 different adjustment
settings for the various colors, and as each photo takes both ink
and time to print, I would like to ask what is the most reasonable
way to proceed when trying to balance out the printed colors to
match what I see onscreen and in print preview (GIMP).
I also note that the photo is in RGB natively, and if I use instead
CMYK settings from GIMP the entire photo becomes washed out white
and gray---the blossoms are correct but the background loses its
In contrast, the Windows driver produces very nice results at
highest quality settings, although it does not have the flexibility
of gutenprint: for example, I have to rescale the image since there
is no support for L size photo paper.
Which print plugin are you using in GIMP, the Gutenprint one or the
one that comes with GIMP 2.4? I have a suspicion that you're using
the GIMP 2.4 plugin, based on various things you've mentioned ("best
color" and CMYK settings aren't available in the Gutenprint plugin,
because they aren't needed). The color adjustments are also a lot
more convenient in the Gutenprint plugin. The CMYK setting will work
very poorly with RGB input; CUPS converts the RGB to a very naive
CMYK, whereas if you use the RGB setting, Gutenprint will do the
conversion, taking into account the printer and paper type. You might
want to install Gutenprint from source and use the "Print with
Gutenprint" option in the file menu.
One thing you might want to try is setting Unidirectional print
direction; bidirectional (which is used by default at 720 DPI and
below on that printer) doesn't produce very good results on older
printers. That will probably get rid of the fuzziness of text and
some of the dotting.
I wouldn't try to print photos at anything less than 1440x720 DPI on
that printer; the drops are just too big. At 1440x720 DPI, the drops
are small enough that you'll get decent quality, nothing close to any
of the modern printers, but quite respectable. The 4-color setting
will produce very grainy output, even at 1440x720 DPI (newer 4-color
printers use much smaller drops).
Setting printing type to photograph sets the color correction to high
accuracy and the dither algorithm to EvenTone, which are good settings
for printing photos. If the image as a whole is tinted yellow-green,
you should reduce the yellow density somewhat and the cyan density
somewhat less (less reduction), and increase the density slightly.
Robert Krawitz <rlk@...>
Tall Clubs International -- http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom -- mail lpf@...
Project lead for Gutenprint -- http://gimp-print.sourceforge.net
"Linux doesn't dictate how I work, I dictate how Linux works."