Digital BW, The Print

> > If the old UT was pre-November 2004, you may have a batch that
> > had a lot of magenta in it -- too much for most people...

> 
> Yes! My UT's *were* pre-November 2004. ...
>Perfect would be the same results minus the almost subliminal magenta bias.

That was the intent with the newer inks.  There is a range of hues that the
papers take on.  Photo Rag, for example with the EEM curve, will print a bit
cool in the shadows, but should be close to neutral in the magenta
(red)-green axis (Lab a).


> 
> > There are differences in UT and UT7 inksets that could show
> > up in curves, depending on how they are written.  The UT toner
> > uses the same mix of color pigments (ignoring the carbon
> > content) as does the UT7 light cool ink (LM). The UT7 dark
> > cool ink (M) and light black use a different and less magenta,
> > more green mix of color pigments... so, if the curves put much
> > UT7 LK or M into the mix above 50%, the tone will be thrown off.
> 
> Clarification: by "above 50%" you mean the highlights, correct?

Correct, keep the M out of the highlights.  In fact, LM and LC are the only
inks that should be at 50%.

One can, in fact, run the LM quite far into the shadows to increase the
relative magenta bias there.


> ... 50% there is a roughly equal mix of all 5 inks.

You might want to change this.

> The worst of the greeny muddiness, though, happens above 50% density...

I'm not sure what would cause this.  With the old magenta, if the light
toner was left still for long periods there could be separation.  I have not
heard of this happening with the new mix, however.

> Yes, I run exclusively with IJC,

Do you have the newest version with the heavier ink loads?  If not, I think
my curves will have the ink limits set way too low.

> ... I'm confused about this LK substitution. 
>I was already considering swapping the
> UT-7-Y (sepia) for UT-FS-Y (light gray), since I don't use the
> sepia.

Yes, that works also, and it's the only way to do it for people running the
Epson driver.

> Did you really mean swapping UT-FS-Y for the UT-7 LK, which
> is a middle gray?

With a rip that allows you to keep the sepia in the mix.  With a rip, it
doesn't matter where the FS-Y is.

> Don't you need the extra density of the LK for the shadows?

No, in a dedicated B&w inkset the LK is a wasted spot.  LK is lighter than
the dark grays we use.  The dark shadows only need C & M.

Paul
www.PaulRoark.com