Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "jrandall1149" 
<jrandall@c...> wrote:> 
--snip
The workflow I used to generate the curves for my Epson 
> 1160 is a partitioned RGB workflow where a seperate "transfer" 
curve 
> is created for each of the three gray inks.
--snip 

Jeff --

Hmmm, the light is slowly dawning.  When I apply a "canned" .AMP 
transfer curve to a 21-step grayscale wedge converted to color in 
Picture Window, the stepwedge visually breaks down into red / 
yellow / cyan bands, each band flowing from dark to light.  I assume 
these are the separate transfer curves designed to partition the 
image into dark / midtone / light sections thereby using the gray 
inks in the MIS cartridge without the dot patterns caused by black 
ink halftoning.  OK, clear enough.

Now the "newbie" questions:

1)  How is what is essentially a CMY breakdown initially created 
within an RGB curves workspace?

2)  When the stepwedge with CMY transfer curves applied is printed 
and, say, the 70% through 85% band and the 40% through 50% bands are 
a solid gray, how is (are) the RGB curve(s) tweaked so that the solid 
blocks resolve into distinct 5% bands?  Can the stepwedge be printed, 
scanned, and some kind of histogram readout give a clue as to how the 
RGB curves can be adjusted to achieve the 5% separation?  

Put another way, is there a feedback loop that will provide 
corrective information on shaping the correct partitioned curves for 
each printer / paper combination, or is it massive trial and error?

Thanks again for your time.

Cheers,
Darrell