Digital BW, The Print

"a_pettit_jr" <a_pettit_jr@y...> wrote:

> The first set of values was obtained from creating an image with CMY
> saturated color blocks, doing a Luminance extraction, and then
> measuring their histogram grey levels...  C = 30 %  M = 59 % 
> Y = 12 %

The C and M gray inks must have been mislabled (interchanged) because 
these relative values are incorrect. C>M>Y (0-100% grayscale values 
where 100% is black)

Let's define your workflow better.  

1) The test above was done with the hex FS inkset for Cone driver 
(where C=PC and M=PM)?
2) You created and printed a CMY color file (with no K block)?
2a) What were your printer settings?  
3) You then cropped and scanned these three blocks with a flat bed 
scanner? 
4) Did you crop each block seperately or did you include all three 
blocks and some white space?
4) What scanner, software, and settings (eg., wp, bp, autolevels, 
color correction, etc.) did you use?
5) What photoediting program did you use?
6) Why did you extract luminance, why not go directly to the 
histogram?

> 
> I just printed the 21-step grey scale by converting to RGB space and
> then to the Epson 2000P. 

7) Which inkset?
7a) What ink positions?
8) Did you apply any curve (like the Woolf hex-inkset lumped (non-
partitioned) curve?  If you didn't, the subsequent results can be way 
off base. You must use, tweak, or develop a work flow including 
curves (either partitioned or lumped) for your inkset and printer. 
You have to tell the Epson driver how to lay down these inks because 
the . 
9) What were your printer settings? 

>The grey range from 65% to 95% is quite
> magenta biased and the 35% to 65% has the cyan cast. The Epson 
driver
> thus seems to expect that the Magenta position will create a darker
> BW shading.

I do not understand how the FS or FS-E inksets can have any color 
cast.  I apologize because I may not understand your terminology.
> 
> I again measured the MIS FS inks and the differing results show the
> variability in my eyeball comparisions ..
> B 100%
> C 30%
> M 8%
> Y 4.4%
> PCe 10%
> PMe 2.5%

9) What image did you measure--the 21-stepwedge?
10) Any difference in scanning from above?
11) I don't understand your numbers, but they do show that C is 
darker than M is darker than Y.  And that PCe is lighter than C and 
that PMe is lighter than M. These are the correct relative densities.
> 
> I intend to install the inkset with the Cyan and PCyan swapped with 
the
> Magenta and PMagenta. There is too much inconsistency between what I
> measure and what the Epson Driver does vs the labels on the MIS FS
> bottles to Not do so....

Put each gray ink in the position labeled on the bottle (after 
checking that the density ranges from dark to light C>M>Y).  Then 
apply a work flow designed for the Epson driver and your printer.  
I'd start out with the Woolf hexset curve. 
> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@y..., "jrandall1149"
> <jrandall@c...> wrote:
> > Alex:  
> > 
> > For both the hex-FS and hex-FS-E inksets the Cyan position ink is 
> > dark gray, the Magenta position ink is middle gray and the Yellow 
> > position ink is light gray. This is not consistant with your 
first 
> > test. 
> > 
> > In the hex-FS, the PM position ink is the same as the M position
> ink 
> > and the PC position ink is the same as the C position ink.
> > 
> > In the hex-FS-E, the PM position ink is a dilution of the M
> position 
> > ink and is therefore lighter and the PC position ink is a dilution
> of 
> > the C position ink and is therefore lighter.  Your second test of
> the 
> > hex-FS-E inks are consistant with this.
> > 
> > Try a swab test using a q-tip and visually compare.
> > 
> > Jeff Randall
> >