Datacolor User to User Support Group.

Yes, I think that helped. Didn't have windex so I mixed up a mild solution of ammonia & dish soap. After cleaning & calibrating on the tile, I get:

Tile itself:     90.85  -1.34   -1.19
Canon Glossy:    94.17   1.83   -7.25
Inkpress Matte:  95.90   3.75   -6.94
Epson Semigloss: 94.18   1.95   -7.51

I'll create a new profile and see how it goes. Thanks.

--Bob


--- In datacolor_group@yahoogroups.com, David Miller <dm2363@...> wrote:
>
> 
> On Dec 19, 2009, at 11:22 AM, Bob wrote:
> 
> > So a few days ago I created a target for the first time in a while;  
> > I'm using the latest SpyderPrint 4.1.1 with an older model 1005; it  
> > has a serial number under 1500. To my surprise, an evaluation print  
> > showed neutral colors coming out rather brown.
> >
> 
> The entire profile will be thrown far off if your paper white  
> measurement has a huge
> color cast (see below). That's why.
> > After repeated remeasurings, I started fooling around with it and  
> > came to the conclusion that at a minimum the white calibration was  
> > faulty; if I use a piece of white paper to calibrate rather than the  
> > original target, the resulting print is much more neutral.
> >
> 
> Shouldn't do that, though. If this "fudges" the calibration so that  
> your paper
> white measurement doesn't have the huge color cast (see below), that  
> still doesn't
> make your overall results correct.
> > I'm not sure, however, if the problem lies in my spectrocolorimiter,  
> > the calibration target, or elsewhere, and would like to know what my  
> > options are beyond buying a whole new kit.
> >
> 
> It's the calibration tile. (Better to call it the "tile", rather than  
> a "target",
> to avoid confusion... better to always, and only, refer to the actual  
> target
> print as the "target").
> >
> > A bit more detail: I'm trying to profile some Epson Premium RC Semi- 
> > Gloss for use on a Canon ipf6100 (there was a great deal on this  
> > paper at B&H). If I use the white target to calibrate, the Epson  
> > Semigloss paper has a LAB around (97,1,-90) -- *really* blue; this  
> > paper isn't exactly neutral but there is no way that it is that blue.
> >
> Yes, that's an incorrect measurement, and it's the reason for your  
> problems. Paper white
> is used as a scaling measurement for the entire profile and if that's  
> wrong, the entire
> profile gets color cast in the opposite direction.
> > Some Canon Photo Paper Plus II, which is visibly whiter, measures  
> > around (97,3,-5).
> >
> 
> That's a good measurement, that's fine.
> > Some Inkpress Matte 80 measures around (98,3,-98).
> >
> >
> 
> That's a very bad measurement, like what you're getting for Premium RC  
> Semi-Gloss.
> > If I calibrate using the Canon paper as the white target, the Epson  
> > semigloss measures around (91,-2,-1), while the Inkpress Matte  
> > measures around (93,0,0).
> >
> 
> Those are obviously not the horrendous values that throw the entire  
> profile off,
> but they're not correct, either. The semigloss would end up measuring  
> close to the
> Canon Photo Paper, and the inkpress matte still wouldn't have a  
> perfectly neutral
> color cast.
> > I'm really not sure what to do here; this does seems surprising  
> > given how far apart these papers are when I use the official white  
> > target to calibrate. And yes, this is repeatable; the numbers change  
> > a little bit but within a few percent the character of the result is  
> > the same, going back and forth between the two calibration targets.
> >
> > Thanks for any suggestions.
> >
> >
> 
> First suggestion is: try cleaning your calibration tile, even if it  
> doesn't look
> dirty. Use some soft cloth and Windex; then recalibrate on the tile,  
> carefully,
> and try measuring those paper whites again. When you calibrate on the  
> tile, pay
> close attention to getting the nose down "cleanly" on the tile, by  
> putting
> the spectro right in the base, with the feet lined up perfectly, so  
> that there
> aren't any gaps around the nose on the spectro.
> 
> 
> 
> David Miller
> Senior Software Developer, Digital Color Solutions
> Datacolor
>