Digital BW, The Print

Having liked single channel black only, I bought an Epson r1800 to use
for Paul Roark's 3 channel, black only prints with Eboni inks on matt
papers.  I use Moab Kayenta and Hprag.  The three cartridges are
positioned in the MK, PK and GLOP position as Paul has specified.  I
have found it necessary to make some modifications to Paul's qidf
files based on Lab luminosity readings from my X-rite Pulse Elite. 
Output scans then showed remarkable linearity and the shadow detail in
my first real print done this morning was wonderful.  I was very
pleased.  Thank you Paul.

Subsequently, I learned from Carl Schofield that I could use PKN inks
in the cyan, red and blue positions.  I used Harman Gloss fibre paper.
 His qidf files printed too dark in the shadow areas.  Not knowing
really what I was doing, I played with the ink limit and gamma sliders
and other things too that I cannot now recall.  I achieved fairly good
linearity, albeit with a couple of small kinks, but the same image as
above printed beautifully, to my eyes).

I then read about applying gloss to gloss and semi-matt fibre prints
and decided I would like to keep that option open.  I could have put
the GLOP `ink' in a cartridge in the yellow position but then I would
not be able to know if any nozzles were not firing.  I therefore cut
and pasted the curve settings from the GLOP position to the yellow
position and put the PKN ink into a `yellow' cartridge.  I expected
the output to be the same as before.  This was a false assumption and
I have tried to linearize the PKN qidf file but without success.  Does
anyone know why moving from one cartridge position to another should
make such a difference?  Anyway, for those contemplating this switch,
beware.  Mind you, I amprobably the culprit.

Ijust could not get fully neutral monochrome prints from QTR with my
2100, some of the range would be green and some warm.  With the set up
  using Paul and Carl's techniques, the hues are consistent across the
print although the hue varies from paper to paper as is to be
expected.  I have stocks of Kayenta and a print on that paper is
cooler, more neutral than the HPR.  I have seen no comments on the La
Sal which replaced it.  Can anyone give an opinion?

Cheers


Colin