Datacolor User to User Support Group.

On Aug 8, 2008, at 5:00 AM, canvaspic wrote:

> Hi all
>
> I have been generating profiles with spyder3print for use with canvas
> on a Epson 9880.
>
> When using a rendering intent of "perceptual", I get clipped shadows
> on the monitor ( CS3 soft proof) and on the print. This manifests
> itself as jet black patches/blotches in the darkest areas of the  
> print.
>
> When I use a rendering intent of "relative colorimetric" and "Black
> point Compensation" is switched on, I don't have the clipping problem.
>
> Q: is there something that needs to be done while profiling to set the
> printer black point for "perceptual" rendering intent.
>
> Thanks ...ed.
>


Our recommendation is to leave black point compensation turned off when
softproofing and printing through our profiles. (This yields a deeper
black; and there should be no clipping in the shadows).

Also, our recommendation is to use the Saturation intent, unless you
see that there are out-of-gamut colors that are changing noticeably in
the softproof. Going to Perceptual will introduce some color mixing to
alleviate this, and going to Relative Colorimetric will introduce the
most color mixing.

If you're getting blotches in the shadows, it could be that there's
something wrong with your measurements (if you can use File:Open
Data in Spyder3Print, and email a copy of your measurement .xml
file to me at davem@..., I'll be glad to have a look;
just make sure you send me the MEASUREMENT FILE (.xml text file),
not the PROFILE that you've built from the measurements).

It could also be that the media settings you're using in the 9880
driver are totally blocking up the shadows; if you're putting down
too much ink, there's no way that profiling can fix this (seeing
the measurements will help diagnose this). You may need to use
different settings in the 9880 driver when printing the target
(and then later, when using the profile) to prevent this.


David Miller
Senior Software Developer, Digital Color Solutions
Datacolor