Digital BW, The Print

Bob,

> I am planning to set up an Epson 7500 printer for quadtone printing.
> The printer is hopelessly clogged in the first two nozzles so I need
> software that will allow me to reassign ink colors and switch off the
> first two nozzles. I prefer to work on a Mac but also have a PC if
> needed.
> 
>...
 
> Does OPM yield as good results as the others?

> The problem is that I have heard that neither of these would give me
> the "grainless" dotless prints I have been getting with the R9
> (Sundance) software. Is it true that the dotlessness in OPM only
> applies to the highlights?

I just printed some test strips on my 7500 comparing the Epson driver and
OPM.  The inkset I have in there has a light ink that is the same density as
the Piezo lightest ink.  With an 8x loupe, I can detect some dots.  However,
the quality in any normal viewing would be extremely good.

The ink arrangement I'm using is what I call the UT-FSN+.  In the C, LC, and
Y spots I have MIS UT-FSN tone inks.  The test strips I was viewing were
glossy prints that just used these tree inks.  For matte paper I add a matte
black (Eboni).  I only use the M & LM, which have pure carbon inks in them,
when I want more warmth.  So, bottom line, your 7500 will be able to print a
monotone, glossy and matte, with excellent results using OPM.

One thing I did to modify the usual MIS-FS/Cone-Piezo ink density
distribution is move the M density closer to the C density.  The original
Piezo densities had the 2 lightest inks very close, and then a major gap
between the M and C.  I moved the middle density to more of a midpoint.  I
did this empirically, trying higher and lower densities and examining the
smoothness of the final print.

Bowhaus has made some curves already for the 7500 and this ink arrangement
and is using the inks.  As such, you'll have ready-made curves (even if you
have to alter their location) with OPM, the UT-FSN+ inkset and the 7500.
(My Photoshop curves probably won't do you any good.)

If you want to see more about the 7500 inkset I'm using and MIS is selling,
see http://home1.gte.net/res09aij/7500-FS-Readme.htm .

While the inkset I'm using is neutral-cool, any tone between carbon warm and
the neutral cool is easy to buy or mix.  Only the LC is a new ink, and it is
close enough to UT7 LC (carbon) density that the old Piezo or MIS FS warm
tones can be made just by mixing the 7500 FSN LC with UT7 LC.  The FS warmth
is 50% carbon, 50% FSN.

At any rate, I can't give a comparison on the 7500, but I started with Piezo
software (R9) and, while it does give dotless highlights, overall I would
rate OPM as far superior.

Good luck.

Paul
www.PaulRoark.com