Digital BW, The Print

Responses to my unequivocal declaration yesterday that I was going to print
using only the black (K) cartridge ranged from (paraphrasing) "whatever
turns you on" to "you must be joking." So I devoted yesterday evening to a
runoff between black-only, the MIS VM inkset, and PiezoBW.

The images had been scanned at 2820 ppi on a Minolta Dimage, then spotted
and minimally adjusted in Photoshop. Histograms exhibited only minor gaps
or "combing," and looked great on screen.The usual output size was 6 x 9",
for a final ppi of over 400 (some very unround number with two digits after
the decimal).

The MIS VM set is still very clever: the image color appears absolutely
uniform over the whole tonal scale. But the images have two problems:

1) Statements to the contrary notwithstanding, the highlights are
definitely not "dotless." Yes, you need moderate magnification to see the
dots, but that's also the case for the black-only highlights.

2) In addition to the dots, the VM set displays what I can only call
"posterization": areas that, on the screen, show subtle variations in tone,
are rendered on paper as comparatively large patches of a single tone. The
effect is that of a silk-screen print; at a fairly fine scale, yes, but on
close inspection the image nevertheless consists of a patchwork of
variously-sized areas rather than an assemblage of identically-sized dots.
I find this very disturbing and un-photographic. I tried downsampling the
image to exactly 360 ppi, but the results were the same.

So I took the exact same file and output it onto the same paper through the
PiezoBW driver using the MIS VM inks. Leaving aside the weirdness of having
the Y (50%) channel print in a bluish color, the results in terms of
continuous tonality were far more acceptable: no posterizing, and in fact
no dots even under magnification. Piezo can produce, in some zones, what
looks like very fine-scale banding (like a quarter of a nozzle was
clogged). My private theory is that this is how Piezo prints so fast: it
somehow "cheats" by occasionally not quite overlapping successive printing
lines. Please correct me...

And finally, yes, the black-only output looks coarse next to either of the
quadtone methods. It's particularly bad right now because the MIS VM black
is quite weak: I have a bottle of Generations black on order that I hope
will come close to the Epson OEM black.

So here's the score:

MIS VM: great inks, clever tonal-adjustment concept; BUT patchy output and
dots in highlights.

PiezoBW: fast, convenient output procedure, excellent tonality; BUT inks
are far too warm and keep fading, and nozzle clogs are unacceptable (I have
had NO clogging problems with the MIS inks).

Please tell me if this is a solution: I get the impression that the MIS
Full Spectrum inkset is _functionally_ identical to the PiezoBW inks (same
ink strengths in the same positions). I also gather from MIS's web site
that their inks can be _tinted_ using their colored inks. So why not tint
each of the MIS Full Spectrum inks sufficiently to balance their inherent
warmness, load them into cartridges, and print through the PiezoBW export
plug-in? I'm sure the Piezo people won't like it, but Epson seems to have
survived the same treatment for quite a while...

Thanks for comments,

-- Nick

NICHOLAS HARTMANN                                +1 (414) 271-4890
611 N. Broadway, Suite 509                  fax: +1 (414) 271-4892
Milwaukee, WI 53202, USA                       polyglot@...

Technical and scientific translator:  German and French -> English