Digital BW, The Print

Mike,

> ... in the light of what I've seen on Roy's "Dots, Dots" page. 
>A few questions have cropped up ...

>First off, how does UT for 4-colour printers achieve variable toning ...

The Y position ink is a cool toner, just like the original MIS VM inkset.
The gamut of the toner is slightly higher because the black and gray inks in
the UT inkset are warmer (the same warmth that the VM inkset would be once
the inkset warms up).

>Next up, regarding UT2 on the same page MIS state that you need to 
>switch blacks to go between matte and RC papers, but Paul's site says 
>that Eboni will do both with the 1280:

>http://home1.gte.net/res09aij/UT2-Readme.htm

Correct.  With the quads you'll need PK for glossy printing.  (Some have
used a post-printing spray with Eboni just like we used to have to do with
the old VM or Piezo systems.)  

With the UT2 and UT7 inksets the systems can print on glossy paper even with
Eboni installed.  This is done by avoiding using the Eboni ink.  The 2
midtone grays are dark enough to achieve a dmax that is about 5% lower than
if the PK were used.  On Ilford Galerie Smooth Pearl, the dmax with no PK
used is over 2.3.

>... is it right that UT1 quad and hex also 
>allow compatibility with all paper types provided Eboni is installed 
>and the correct curve adjustments are made?

No.  The UT1 inkset requires PK to print well on glossy paper.  Only UT2 and
UT7 can print well on glossy with the Eboni installed.

>Thirdly, looking at the evolution from VM to UT, and considering 
>Roy's comments about the lighter grey provided in the VMS set for the 
>1160, is it true to say that the lightest UT grey is darker than the 
>lightest VM grey in order to allow the "Easy B&W" functionality?

The lightest UT2 and UT7 grays are darker than the VM and UT1 lightest gray.
This is needed to get the sepia in there and to allow printing without the
use of curves -- the "EZ" mode.

This is why the UT2 is for the 1280 only.  The 1280 is good enough that the
light ink needed for the old quads (like the 3000) is not needed for
visually smooth prints.  Of course, the 1160, with its rather modern
variable-dot design, can achieve smoother highlights with the lighter gray
ink.  However, there is a point where more smoothness just doesn't add any
significant value, whereas the alternative uses of that ink position does.
So, the UT2 design, for me and many others, is better compromise of features
and makes prints that, overall, are better than the 1160.  I will probably
throw my 1160 in the trash now instead of fixing it again.

>I'm mainly looking for smoothness ...

Get some samples from people.

Paul
www.PaulRoark.com 

For UT2 & UT7 information, curves, and settings see:
http://home1.gte.net/res09aij/