Digital BW, The Print

> > So, with UT7, the route to the best dmax I'll be taking 
>>with matte papers is to just add M (dark cool gray) to the 
>>black point via a rip.
> 
> How much do you add?

If you mean dmax, it adds up to 0.06 density units where it is needed the
most.  So, PremierArt 205 which hits only 1.50 with UC MK, hit 1.55 with
Eboni and the Epson driver, and is up to 1.61 with the rip, Eboni and UT7 M.
PermaJet and Innova papers go from about 1.61 with Eboni and the Epson
driver to about 1.66.  With Photo Rag it appears to add almost nothing.  PR
gets 1.64 - 1.65 with Eboni with either the Epson driver or the rip, but
more experimenting might increase this a bit.

>Do you run it full strength?

It takes very little UT7-M to do the trick.  It varies, but usually backing
off the K ink load from 26 to 25 makes "room" for the UT7-M addition.

> Does it work the same way on the 2100?

The 2200 (and I assume the 2100 is the same) does not have the same dmax
problem that I'm seeing with the 7600 and 4000.  So, I have not experimented
that much with it -- unless I've intentionally crippled the machine.  To
"simulate" the 7600 I used the 2200 with the black ink load backed off from
26 to 20 in IJC.  This allowed a lot more experimentation that changing
carts on a 7600 could do.  However the simulation was not entirely accurate.
It is not just an ink load issue that differentiates the printers.  

The trick with the 7600 is to reach the dmax levels that most older printers
can reach with the Epson driver and no tricks at all.  For most of the older
printers, the EEM or Matte Paper Heavyweight ink loads put the papers at
about the most they can achieve with any combination of pigments as far as I
can see.  If you add more ink to these loads, the dmax usually drops.  That
is, you've reached the top of the hill.  

With the 7600 and 4000, the top of the hill is lower if only one ink is
firing.  The way to get that top higher seems to be to add a second ink,
even if the density of the second ink is less.  The second ink seems to be
filling in spots that were not well covered by the first. 

Note that the time the first ink has to sink in before the second hits the
paper is one of the variables.  With the 2200, I found that the dmax and
optimum load increased slightly as the second Eboni was moved from the LK to
the Y spot.  Y is the last jet to fire.  I speculate that part of what is
going on is the time it takes for the ink base to be absorbed.  

Especially with the UC MK, the cyan also seems to be doing some of what the
cyan does for the PKN.  It is probably due to the relative colors of the
inks.  UC MK is so warm that the cyan may be mopping up that warm color.
I'm obviously speculating a bit here, but the UC MK + C combination is the
most dramatic improvement I've seen.


Paul
www.PaulRoark.com