Datacolor User to User Support Group.

Question on printing targets...
 
I printed the 255 color target on my R1800... looking closely at it I 
don't see that it actually printed the Gloss Opt layer anywhere on the 
chart except for the area around the logo in the bottom right corner - 
the logo has been GO'd - but it does not look like the patches have... 
looking at the one patch which is 'white' and I assume has no ink - it 
looks exactly like the rest of the paper (Prem Glossy) - I would have 
expected to see the GO box there. 
 
I have the GO setting on the Epson R1800 driver set to AUTO - I printed 
the targets from PrintFix Pro 2.0 software.
 
Any thoughts out there? 
 
I would think I would need to measure the colors w/ the GO to be the 
most accurate. Or perhaps I an just not visually seeing it.

>Question on printing targets...
>
>I printed the 255 color target on my R1800... looking closely at it I
>don't see that it actually printed the Gloss Opt layer anywhere on the
>chart except for the area around the logo in the bottom right corner -
>the logo has been GO'd - but it does not look like the patches have...
>looking at the one patch which is 'white' and I assume has no ink - it
>looks exactly like the rest of the paper (Prem Glossy) - I would have
>expected to see the GO box there.

We have no control at all over this; we're just printing at the application
level; we don't control the inks, GLOP, or the driver itself. Whether or not
you get GLOP anywhere on the chart has to do with the R1800 settings in
the Epson driver; and the Epson driver itself (i.e. what media type you
choose).

Best regards,

-- 
David Miller
Senior Software Developer, Digital Color Solutions
ColorVision

CDT and David - thanks for response. I find the it does not seem to 
affect the overall reading as you indicate.

--- In colorvision_group@yahoogroups.com, CDTobie@... wrote:
>
> 
> In a message dated 1/11/07 10:43:35 AM, doug@... writes:
> 
> 
> > 
> > I have the GO setting on the Epson R1800 driver set to AUTO - I 
printed
> > the targets from PrintFix Pro 2.0 software.
> > 
> > Any thoughts out there?
> > 
> 
> Well, my main thought is that way too much consideration has been 
given to 
> GLOP and its effects on profile building already. GLOP is mainly to 
fix an 
> optical effect (I'm tempted to say optical illusion <G>) in which 
inked and uninked 
> sections of the image, at close proximity, under extremely low 
light angle, 
> show an unpleasant difference in surface reflectivity. 
> 
> Patchreading devices work at a very precise 0/45 configuration 
where all the 
> light is supplied at 45 degrees to the surface, and all 
measurements occur at 
> zero degrees (perpendicular) to the surface (or in rare cases, the 
reverse). 
> So gloss differential won't even be perceived by a spectro, and the 
angle is 
> too tight. The white patch will, theoretically, read as a slightly 
different 
> white when GLOPped or not GLOPped, but if you put an image with 
GLOP on the main 
> image, but not the border, in a light box where the lightsource is 
45 degrees 
> from the image plane, and your eye is perpendicular to the image 
plane, and 
> attempt to distingush where the edge of the GLOP zone is, and what 
difference 
> there is in the color of white in the two sections... well, I don't 
think you'll 
> see much that would concern you.
> 
> Other details of the profile calculation process minimize the 
difference even 
> further. So overall, my level of concern about whether GLOP is or 
is not used 
> in the profiling process is pretty low. Whether its used in a given 
print is 
> a matter of how the print will be presented and displayed; if low 
level light 
> and low level viewing angles may occur, then GLOP is a real 
benefit. But in a 
> step-back matting system, under glass, on a wall with proper 0/45 
lighting 
> viewing angles (as in a gallery), its as moot for viewing as it is 
for profiling.

> 
> C. David Tobie
> Product Technology Manager
> ColorVision Business Unit
> Datacolor Inc.
> CDTobie@...
> www.colorvision.com
>