Digital BW, The Print

Alex:

My working knowledge of the Epson driver (others please step in and 
help/correct me because I am beyond my detailed technical knowledge 
of drivers) is that it does not not see in grayscale, meaning that it 
does not cause the ink in the Cyan position to fire when it is sent a 
certain brightness/luminosity/lightness/density value. It fires when 
sent a CMY color of a given brightness. In grayscale mode, I suspect 
that the CMY information is close to equal creating various shade of 
gray depending on the brightness information sent to the driver.

I haven't checked it out, but I suspect that the Woolf workflow would 
work with the gray inks in any positions (but K=K) because it treats 
all the gray inks essentially the same -- hence the brightness of 
each Woolf dot is the same until K kicks in at about 50%.  BTW, the 
Woolf curve is not very aggressive and seems to fit my understanding 
of your goal of mild correction.

The only way that I know of to control the individual inks in any 
particular position with the Epson driver is to assign colors & 
brightnesses to the grayscale image--this is called partitioning. 
Roark, Brandon, and Randall workflows (found at MIS 
www.inksupply.com) are examples.  

You may have hit on something about the sequence of ink deposition 
creating an additional variable.

Jeff Randall


--- In DigitalBlackandWhiteThePrint@y..., "a_pettit_jr" 
<a_pettit_jr@y...> wrote:
> Hi Jeff,
> 
> You have identified the problem in attempting to use Woolf's 
correction curves : they are just S curve contrast corrections. If 
the inks are misplaced, this type of workflow cannot correct the 
error. It would take the sophisticated RGB color corrections of Paul 
Roark to compensate for inks in positions 'not expected' by the Epson 
Driver.
> ( IE, the Epson driver is going to squirt from the Black position 
even if I install Yellow ink and no greyscale control can correct 
that )
> Thus my hypothesis: if the inks are incorrectly located, a simple S 
curve tweak will be fully ineffective. I am hoping to get as close as 
Epson 'expects' the inks to be and then use some mild correction 
curve if needed.....
> 
> Maybe the 2000P, being pigment based, uses drivers which deposit 
inks in a sequence differing from the other Epsons and thus the 
classic hex grey sets have not worked optimally ??
> 
> Best,
> Alex
> 
> 
> --- In DigitalBlackandWhiteThePrint@y..., "jrandall1149" 
<jrandall@c...> wrote:
> > Alex:
> > 
> > Isn't Woolf's workflow curve just a slight tweak up from your 
goal of 
> > printing a 8-bit grayscale image with the Epson driver with no 
> > correction? If you are planning to control each ink seperately, I 
> > think you will have to convert to 24-bits and "color" the 
grayscale 
> > image so the Epson driver knows which ink to laydown (this is 
called 
> > partitioning).  The Epson driver sees in RGB (converted 
internally to 
> > CMY) not in grayscale when in the color mode.  
> > 
> > Jeff Randall 
> > 
> >