Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Greg"
<dfaprinting@...> wrote:
...
> OK, most of you can tune out now.
> 
> You can get pretty close with certain GCR settings, but you need to 
> use a profile app. that lets you make a custom GCR curve....

Most do, and I do understand how it works. But even if you manage to
write a curve that copies Epsons, you still won't achieve any setting
that gives 100% total ink in one part of the scale (in this case rgb
000) and say 250% ink in a lighter part of the scale.
By the way, I hope I didn't sugeest that copying the Epson driver
behavior is desirable.
And since total ink amount is our only control of CMY content at max
K, with some inks and papers we can lower our dmax by raising total
ink just to achive gamut.
David Tobie could us tell a lot more about the driver's behavior than
I could.

> As far as ink limits go... There are some tricks that I use with my 
> inks, but I don't know if they apply to the Epson inks, so I won't 
> spill all that out for fear of causing confusion. Summary is that not 
> all inks hit their maximum density in the same place as their maximum 
> chroma.

Right, Epson inks hit max chroma before max density and begin to reverse.

> You need to find a good balance between those two values. 
> With the rather different inks that I use, you also do not want to 
> run the light cyan all the way down to the maximum full cyan as it 
> takes away from the blue coverage.

With SP, light inks are taken out porportionally to the dark component
coming in. Not user changeable. So I would never run into that
particular problem.
A potential problem here is that if you let all light inks run to too
high of an individual percentage (for color printing) you could
unwittingly find yourself with very high total inks in mid range
colors you would not normally suspect. So yes, many issues.

> ... I had to learn a very large amount to get 
> the inks I'm using to work properly,

I can certainly apreciate that.

> ...Understanding how the 
> RIP is doing it's job is very important, and often the only way to 
> know this is to make many different configurations to see which one 
> works best. It can be a slow process where gains can be very small.

I'll admit to burnout right now. I'm going to number (1/1) and sign my
linearization and profile charts and foist them off on an unsuspecting
public for thousands. No one's are quite like mine, and each a one of
a kind.
Tyler