Digital BW, The Print

The QTR/Linux printing from commandline is a bit too primitive
for me. For the moment I'm back to the Wasatch SoftRip for quad
printing. I made new CMYK correction curves in the RIP and made
the best of the 4 channel, very much colour printing (auto black
generation etc) architecture of that RIP. At least it makes
linearising with the Spectrocam possible. Though for the coolest
curve I need the toner channel in non linear fashion. Then it is
cooler than Paul's curve and cool into the black. The Eboni black
in all the 4 curves is at least 1.85 on PhotoRag, checked it with
a densitometer and Kodak's reflection guide as a reference. Is
that a number that QTR users also get ?  I have to add that at 60
% of the greyscale the ink quantity is then a bit too much, just
before the black sets in. A detail greystrip with white lines
through the steps shows some bleeding there. The neutral curve is
showing it most. The dithering of the Wasatch isn't as good as
Epson's or Gimp-print.

After this exercise my esteem for Paul is even higher than it
was. How on earth can you think in grey inks controlled by an
RGB/CMYK colour driver like Epson with its hidden inklimits and
black generation and do the steering by shifting RGB curves ?  On
the other hand I also think that the Ultratone VM set is very
much compatible to that method and could have more suitable mixes
for other methods like QTR or another RIP. The toner set for
instance could be stronger with more blue pigment to keep the
total ink quantity lower. If that is possible.

I have printed some geometric art samples that have a more or
less random distribution of 205 greys in squares. If the
greyscale isn't linearised properly it shows in those samples
right away. Could put a strip of that in the files section for
others to use it. If the artist agrees.

The best that could happen now to QTR on Linux is that the
Gimp-print plugin of the Gimp functions with QTR. Even better
would be a 16 bit dedicated Greyscale viewer with a similar
driver menu and a display that shows the toned image based on the
0-100 % tone scale setting.

Ernst