Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "brouwerkent" 
<philip@...> wrote:
>
> I have been thinking of buying a 1400 and dedicating it to 
> printing on Lustre papers, ie Ilford Gold Fibre and the like.
> 
> Since I am starting from scratch if I make up an ink set, 
> I am wondering if PKN would a suitable ink as a most 
> neutral starting point for my black.

I'd avoid MIS's original "PKN."  It was fine for the older printers 
and for the K position.  It's too cyan/green for dilution, and it's 
not a modern ink in terms of the carbon load.

The UT14-C has the right mix of color, but it's colder than you'll 
want if used alone for all the dilutions.  However, as the coldest, 
darkest modern "PKN," it's the place to start for a cool PKN.

I think it's tough to make a glossy-compatible monotone that is going 
to look the way you want it to across the board.  For example, the 
UT14-C is 40% color, 60% PK.  That is what you need for a "neutral" 
highlight.  But, it's too cool for the midtones.  So, if you want 
a "neutral" that keeps to a straight line from paper white to black, 
you'll need to have different ratios of UT14-C to PK for the 
different dilutions -- probably too much work.  

The 260 UT-RC neutral and cool inks use the same blue/cyan ratio, but 
have 20% in the "neutral" and 30% in the "cool" versions.  You can 
see at http://www.paulroark.com/BW-Info/R260-BW-GS-Eps.pdf what the 
tones will be.  Even with "cool" in the midtones and "neutral" in the 
K position, the papers still print with a mild split tone.  (The UT-
RC 260 inkset is, otherwise, different from the UT14 -- different 
dilutions.)


I prefer the variable tone approach, particularly for glossy prints 
(where the 100% carbon is still too difficult to be a widely used 
approach).  With UT14 it's simple -- 40% color in the C channel, pure 
warm carbon in the M channel.  Software (curves and profiles) are 
much more flexible and easier to change than ink mixes.

A lot depends on whether you want to use the Epson driver.  I'm 
working from memory here, but I think the 1400 did not deliver a good 
dmax with just a single PK.  That's another reason why UT14 has, in 
effect, both a PK and PKN.

Below, it looks like you're a QTR user.  That helps.  QTR can deliver 
the load needed to get a very good dmax with UT14-C (the new PKN).


> I would use Glop as 
> the dilution mixer to minimize the gloss differential.

Yes, and the Epson driver usually works well with a mix of 30% the 
next darker ink and 70% glop.

>   I note with interest the idea of using Eboni in all 
> different dilutions, ...

Eboni is matte only.  PK and the color inks are the starting points 
for glossy inks.  The UT14-C is, in effect, a PKN with the correct 
mix of blue and cyan to give a relatively straight line response if 
desired.  Getting the cyan/blue (I prefer MIS R800 blue to its 
magenta) is tricky.  So, starting with this UT14-C ink is a simple 
way to know solve that problem.

 
> Any thoughts on an ideal Lustre B&W ink set.

UT14 assumed matte as an option would be desirable. Aside from that, 
it's going to be hard to beat.  Putting a more dilute ink in Y 
instead of glop might make a difference under a loupe, and glop is 
not as necessary with UT14 as it is with some other systems.  With 
QTR you can increase the number of dilutions and keep glop in there.  
Without a rip, you might run into a weak glossy dmax with only a 
single K.


> Regarding Glop, I have used it in the mix of lighter inks with
> some success on a 2200.   But I have never completely 
> eliminated gloss differential on the pure white areas in an 
> image.

>  I note that HP Z3100 series has a Glop channel and looking 
> at prints from that machine, gloss differential is entirely gone.

Although I can't say it's a perfect solution, glop does help, more so 
with some papers than others.  That's why its in UT14.

>  Using QTR, is  a reversed curve with the Glop channel the 
> right idea...so that it lays down 
> more glop on highlights including the paper white areas.  
> Has anyone experimented with  making Glop curves.  
> The only issue I see with doing this is not really knowing 
> if the ink channel is working, since it would be impossible 
> to see a nozzle check.  

I think QTR turns all channels off at the white point (255).  So, I 
think you have to start your image at 254.  I've never used QTR with 
glossy inks and glop, however.

Good luck with the project.

Paul
www.PaulRoark.com