QTR-Quadtone RIP

JD-

The problem you are having is because the LAB values are actually out 
of order (which QTR Create ICC after versions 2.3.0 will not 
tolerate).  If you look at the LAB values in the Measure Tool text 
file I think you will see that in the shadow range (L* 18 or lower) 
the numbers are not consecutively smaller as they would be if the 
patches were  consecutively darker.

I have not found this "reveral" of shadows with Epson papers, but I 
have had it on HPR and several other good papers printed through the 
ABW driver.

So your choices are:  linearize the printer with QTR; try different 
ABW settings (I find the light setting more linear than the darker 
setting); use a different paper (the Epson VFA, if you like the 
texture, produces a very linear response and the best DMAX, used with 
K3 inks, of any paper/ink combination around; or manually adjust the 
numbers in the text file to make them just linear (e.g. if they are 
15.35, 15.90 and 15.40, change them to 15.35, 15.34 and 15.33).  The 
latter option is a bit of a cheat and will reduce the shadow 
linearity and separation, though I'm not sure to an extent that is 
visually detectable.  Incidentally, I have *not* found that reducing 
the ink limit (in the ABW driver) corrects the reversal problem.

Walt



--- In QuadtoneRIP@yahoogroups.com, "jdaalder" <jdshop@h...> wrote:
>
> Hi
> 
> I've got an Epson 7800 and an Eye One unit and I'm trying to use 
QTR's
> create ICC program (on Windows XP) to create an ICC profile for the
> ABW mode.
> 
> I've printed the step wedges (51 grey random) with no colour 
management.
> 
> I've used measure tool to measure the patches (in reflective mode, 
no
> spectral).
> 
> However when I drop the .txt file on to QTR-Create-ICC.exe, it 
always
> gives me a .txt output file saying 'Lab values not in order, cannot
> create profile'.
> 
> I'm sure it is something obvious but I can't figure out what is 
wrong,
> nor can I find anything obvious in the eye one notes or the two 
yahoo
> groups.
> 
> Thanks for any help!
> 
> Cheers
> JD
>