Digital BW, The Print

Rick Colson [mailto:colson@...] wrote:

>Does anyone on the list know what solvent or base Epson uses for its black
>ink for the 7600 or 9600? I would like to try to dilute stock Epson ink for
>use with a Piezo driver. Any suggestions? Thank!

Assuming you are talking about the UltraChrome black, some relevant
information follows:  The foreign Epson sites have interesting information.
See the Australian and Hong Kong sites.

For matte paper you want to use the UltraChrome matte black.  It is a
non-coated, larger particle, but still well within what normal printers can
handle (about 140 nm or 0.14 microns).  The other black -- coated for glossy
paper -- has a significantly lower Dmax on matte paper (and may have more
metamerism due to it's coating).

The surface of the matte black particle has a special "water solubility"
layer.  I think this is a big hint that the base is water-based.  Standard
MIS clear base may be compatible.

The deep black of the UltraChrome ink may come from the fact that the base
can hold a higher particle load than the bases we currently have.  To me,
this suggests that the viscosity is higher, but maybe not.  That special
surface on the particle may be part of the secret.  At any rate, the
printers are quite sensitive to viscosity.  MIS is experimenting with an
UltraChrome clone inkset.  They will try the clone in a 1280 and let me know
what happens.

By the way, the color UltraChrome particles that are coated with a resin
have color impregnated in the coating.  That appears to be where the
relatively high gamut comes from.  It also appears to be why the
UltraChromes are less archival than the old 2000P pigs and new 10600
"Archival" pigs.  (The 10600 is a hextone with a larger drop size.  The lack
of a light black, among other things, makes it unacceptable as a B&W
printer.)

Perhaps because the black ink does not have colorant in the resin, the
longevity is greater than the color inks -- in excess of 100 years.

The DX3, variable-dot size, 4 picoliter drop size, and 2880 resolution of
the 2200/7600 may, indeed, allow the light black to go all the way up into
the highlights in B&W printing when in 7-ink mode.  As such, there may be
little need for Epson to have an 8-ink machine or a low-gamut inkset.  It
may not be relying on the color ink for any more than tinting, even in the
highlights.  Epson is clearly promoting the 7600 as a B&W printer, and it
may be able to do it all.

The UltraChrome black ink is the only ink that is really of interest from
that inkset for those of us doing quad printing.  The PiezoTone midtones,
according to my initial testing, are about equal to the UltraChrome midtones
in longevity.  I'll keep the PiezoTone test strip in the fader as I do
longer term testing of the UltraChrome inkset.  So, there is no need to
dilute the matte black to make midtone inks.

We'll know more about the viscosity of the UltraChrome inkset and whether it
will work in standard printers soon.  Also, the third party ink industry is
right behind Epson in utilizing the new bases that can hold more black
carbon particles.  So, new blacks are, no doubt, in the pipeline.

Paul
http://www.PaulRoark.com