Datacolor User to User Support Group.

I'm creating QTR profiles for a few matte papers and I'm intermittently
having difficulty reading the paper base. I will either get a very high
reading (e.g. Premier Art Hot Press 205 - L 2.10, A 6.78, B -12.77) or the
correct L* reading for paper base but a very high A (e.g. Innova Smooth
Cotton Bright White - L 99.90, A 84.91, B 0.43). The correct reading for
SCBW is L 99.86, A0.6, B 0.33 and for PAHP it's L 98.72, A 0.99, B 0.28.

I've been working on this for the last 3 weeks on and off, and only lately
(last week or so) has the above occured. It's intermittent, but it seems to
be getting worse. I use a second sheet of the same paper type underneath.
Readings from my step wedge, other than 0%, are all fine. I re-calibrate
when I start a session. I have completely powered my PC down and back up. No
improvement. I am having the same problem with Innova Soft Texture Art and
Cold Press Art as well.

Suggestions?

Thanks,

Terry.

Problem solved fyi. I had something covering part of my white calibration
pad. 

What is the proper way to clean this pad? Is there a way to ensure I'm fully
calibrated again?

Thanks,

Terry.

> Terry Ritz
> 
> I'm creating QTR profiles for a few matte papers and I'm 
> intermittently
> having difficulty reading the paper base. I will either get a 
> very high
> reading (e.g. Premier Art Hot Press 205 - L 2.10, A 6.78, B 
> -12.77) or the
> correct L* reading for paper base but a very high A (e.g. 
> Innova Smooth
> Cotton Bright White - L 99.90, A 84.91, B 0.43). The correct 
> reading for
> SCBW is L 99.86, A0.6, B 0.33 and for PAHP it's L 98.72, A 
> 0.99, B 0.28.
> 
> I've been working on this for the last 3 weeks on and off, 
> and only lately
> (last week or so) has the above occured. It's intermittent, 
> but it seems to
> be getting worse. I use a second sheet of the same paper type 
> underneath.
> Readings from my step wedge, other than 0%, are all fine. I 
> re-calibrate
> when I start a session. I have completely powered my PC down 
> and back up. No
> improvement. I am having the same problem with Innova Soft 
> Texture Art and
> Cold Press Art as well.

--- In colorvision_group@yahoogroups.com, "Terry Ritz" <t.ritz@...> 
wrote:
>
> Problem solved fyi. I had something covering part of my white 
calibration
> pad. 

Terry, I found myself in the same situation, mostly ink transferred to 
the pad which wiped clean with a tissue and a bit of friction.  I am 
also curious about the material used in the calibration area.  It feels 
to me like Delrin or possibly one of the UHMW plastics.  Both should 
wipe clean easily but I know that Delrin does turn whiter and chalks 
after long exposure to the sun.  There must be a Master somewhere or 
some formulation for calibration of the disks and with that I would 
assume a way to re-calibrate the disk after a given time.