Digital BW, The Print

> From: Clayton Jones [mailto:cj@...]
>
> Now I'm testing a new paper and with the same image the background
> looks considerably weaker, so I conclude that this paper has poorer
> Dmax than PR.  Just to experiment, I add a curve layer and give it a
> bit of a contrast boost to see what happens.  This is a typical
> S-curve where the black and white anchor points are not moved.  So all
> 0 pixels in the background are still zero.  Theoretically nothing in
> the background has changed (the rest of the image _has_ changed, of
> course).
>
> Now when I print this, the background Dmax has increased considerably,
> enough to where I'd think it was a different paper.  What has happened
> here?  How can more ink have been put down in an area that was already
> solid black?  Of course the other part of the pic is too contrasty -
> you can't make a silk purse out of a sow's ear.  But I'd sure like to
> understand better what's happening.  Anybody know?

If I print a test target in NCA mode on my 2200, the 0,0,0 patch generally
looks a tad lighter than the nearby black patches. It appears that 0,0,0
translates into pure K, while other small values produce CMYK combinations
that are actually darker. I would think that good profiling software would
be smart enough to avoid pushing the printer into its pure K output range,
but apparently it isn't.

--

Ciao,                   Paul D. DeRocco
Paul                    mailto:pderocco@...