Digital BW, The Print

> You may have noticed that once the 7600 was out I purchased a 
> 7500.  I don't think the 2100/2200/7600/9600 driver is going 
> to lend itself to the standard variable-tone inkset arrangement.

I agree. On the other hand it lends itself extremely well to changing
between different carts. So keeping carts with different tones would not
be a big problem. Another great thing about the printer is that it never
clogs, even with all the refilling and changing of inks I've done lately
I still haven't had a single clog. At most I have to run an occasional
extra cleaning cycle when I change a cartdrige to get a prefect nozzle
check. 

> To control the tones in the shadows you need to be able to 
> have the toner full-on as far down in the shadows as 
> possible.  Usually you're just fighting the black ink, which 
> is warm.  As the black is fed in, the color inks are cut back 
> to stop over-loading the paper.  Part of the original VM 
> toner design was to get the gamut of the toner to just enough 
> to give a neutral 90% patch with the 1160 workflow that I was using.

I think a variable tone inkset where you have to change between warm and
neutral black and light black cartridges is the way to go for this
printer. Personally I hardly ever make warm prints, and I really like
the selenium tone piezo inkset, so I would probably go for some black
tones to match that and use them permanently, except for the occasional
warm print.
 
> With the 2100 starting to feed the light (warm) black in 
> earlier, this is going to be a problem.  Also, the cyan tone 
> of the standard variable-tone, vm inksets is slightly darker 
> than the light black.  This is might make shadow contrast 
> hard to maintain with some tones.  Bottom line -- the inkset 
> is probably going to have to be modified to work with the 
> UltraChrome drivers.

Would it make more sense to use gray inks that matched the densities of
the cyan and photo cyan positions in this case? 

> > I've been wondering whether I
> > could mix a more neutral light black ...
> I think a more neutral light black would help.  There may 
> still be density anomalies, however.

I tried mixing one last night but it did little to affect the warm
shadow areas although the ink itself looked much cooler. In fact, after
that I tried a light black cartridge filled with pure UT magenta toner
ink, and still the darkest shadow areas looked brown, although the rest
of the curve was dramatically cooler. Could this be interference from
the dark cyan? Or would I need to mix a cooler Photo Black as well?

> To be frank, I'm not sure the 2100, et al., will really be 
> that useful until a good RIP is out that can control each 
> cart individually.  If we get such a product and it's 
> reasonably priced, I might just go that route with the UC 
> printers.  On the other hand, I may just skip the 7-ink 
> printer generation entirely.  The 8-inkers may be out soon enough.

I'm eagerly awaiting IJC for windows... I suspect it might take time
though, so in the meantime I'm going to continue my experiments to see
if I can find a working solution.

> >What would be the best way to mix a neutral ink?
> Try throwing cyan and magenta MIS 7600 color pigments into 
> Photo K.  Expect to put a little more magenta than cyan into 
> the mix.  You can add one-drop amounts (I use a flat 
> screw-driver to get good, consistent drops) into a bottle cap 
> to mix small samples and then spread them on a piece of EEM 
> with to Q-tip.  When the tone looks right, just scale it up.  
> You can get fairly close this way.  I'd take a wild guess 
> that close to 20% color pigs might be what you'd need.  These 
> will make the Photo K lighter.  You may want to end up with a 
> mix that is darker than the cyan UT ink.  (All the crossovers 
> in that driver could continue to make things difficult.)

My first try wasn't that successful, but I'll keep experimenting. 

> Good luck.  Let us know how it goes.

Thanks! I will.

--
Daniel Staver
Petraflux Web-design | http://www.petraflux.com
Tel +47 22 35 44 57 | +47 Fax 22 35 40 66