Digital BW, The Print

"Michael T. Murphy" <uriel_bear@...> wrote:

> > "pr_roark" wrote:
> 
> > A couple of us are looking at using the C6 
> > base to dilute PKs for use in warm carbon 
> > channel to go with the HP cool dilutions.  

> ...
> I have been looking for a good "photo black" only (glossy and semi-
> gloss) ink set.  ...
> 
> I mixed up a test "glossy" ink set for my 7600 using the 
> Epson PK and the C6 base ...  
> ... 
> The PK mixture was a bit brown and green, ...

On my draw-down test of the 10% Epson PK, 90% C6 base mix on EEM, I 
measure a Lab A = 2.1 and Lab B = 2.8.  So, I don't see any green, 
though it is warmer than I like.  Maybe this is mostly a matter of 
what paper is used, and I did not test this mix on any glossy paper.  

Did you have any problem with clogging or inconsistent ink densities?

> I am going to try the same kind of mix using the HP PK, as you have 
> outlined.  
>...

> I am not ... obsessed with longevity and will probably just 
> use color inks as toner in the 6th "K" channel if needed.

I think the Wilhelm HP numbers give sufficient confidence for most.  
One of the major concerns with color inks in B&W is the differential 
fading and green or other tone shifts.  In this respect, not only do 
the superior HP color ratings give confidence, but a major part of 
the HP effort here has apparently been to get color pigments that 
will fade evenly.  So, they've really focused on the issues we've 
discussed here over the last several years.

Keep us posted on your progress.  Right now my test 220 is sitting 
idle for the month to see if it'll clog with the HP mix.

Paul
www.PaulRoark.com