Digital BW, The Print

I've been printing with K3 inks on an Epson 2400 in ABW mode,
and have been very pleased with the results on glossy paper. I
decided to give MIS K4 inks a try, both because of the reduced
cost, and because of the hope that I would get better results on
matte papers -- in particular, a flatter look in the black and
eventually (when I follow Paul Roark's advice and switch the
yellow for a light carbon) better neutrality.

But my first experiments have not been encouraging. I get a very
slight but unpleasant greenish-blue cast in the shadows. I
suspect it's noticeable only because the lighter tones are so
warm. I'm surprised by this because I thought that MIS Eboni
would be _warmer_ than Epson MK, so I would expect that if
ABW mixes in some color to cool off the ink in the shadows, it
would result in less cooling in the K4 case.

When I print a 21-step ramp, the color cast is evident in the 85%
patch, with the A* value dipping below the axis to about -0.5.
Both A* and B* are positive elsewhere with reasonable values
(between 0 and 2). These readings are on EEM; Photo Rag shows
a similar effect.

I'm wondering if I have a bad batch of Eboni. When I paint some
of the ink straight onto paper with a cotton bud and take
readings, I get A*=0.7 and B*=1.6, which seems reasonable.
When I print in black only mode, the print doesn't look very
warm at all, which is surprising. (But maybe selecting "black"
mode in the driver doesn't actually restrict the ink to black?)

One other piece of information: I still have some of the original
K3 cartridges in: M and LM, following Roark's advice that they
are better magentas than MIS's, and C.

Any advice would be very welcome...

--Daniel