Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, peter 
nelson <peter@s...> wrote:
> At 02:00 AM 2/11/2003 +0000, 
DigitalBlackandWhiteThePrint@yahoogroups.com 
> wrote:
> >Besides, ImagePrint and PowerRIP can do it, so it's not like 
it's
> >impossible either...
> 
> 
> I'm still waiting for someone to explain how they get around
> the metamerism problem. (assuming they do, which is
> why I wanted Colorbytes to send me samples so I could
> see for myself.)  Several theories have been advanced, mostly
> involving not using one color or another but no basis has been
> provided for any of these theories, even though they would
> be EASY for IP owners to test.

I have a B&W print from the 2200 using the ImagePrint 5 RIP.
It's quite cool/neutral and doesn't suffer much from metamerism.
Looking with a loupe there doesn't seem to be many color
inks dots.  I don't know the internals of either the Epson
driver or of IP5 so I can only speculate based on what I see.

I t appears that the Epson driver uses quite a bit of CMY inks
as well as the light black ink to produce intermediate grays.
Colorbyte with their IP5 product has on the other hand tried
to woo the B&W people --- and made a point of using the
light black ink as much as possible to replace the CMY inks.
I.e. they don't mix CMY to make gray at all they just use a 
lot more light black.   The other part of the answer is that the
black and light black inks are very warm colored i.e. they 
already have a lots of yellow in them.  So IP5 uses very small
amounts of C and M to get the correct neutral gray.  So this
is why you get the quote "it uses no yellow ink".  I don't
know if the yellow ink really is bad -- I suspect its just a 
matter of not using much color inks at all.

So its pretty much that IP5 provides a good two ink duotone
system out of the 2200.  I use an old 1160 with three gray
inks and a sepia ink.  This is a very good three ink tritone
system that stands up very well to the new stuff.

Roy