Digital BW, The Print

----- Original Message ----- 
From: "Carl Schofield" <scho@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Thursday, November 13, 2003 5:37 PM
Subject: Re: [Digital BW] QTR Ultratone Dmax on PhotoRag ?


> Ernst,
>
> With the 2200, the Dmax for H Photo Rag was 1.63 - 1.64, using
QTR
> beta8  and Epson UC inks (matte black).  EEM gives Dmax 1.68 -
1.70.
> These Dmax readings are from the 100% black patch in the 21
step gray
> wedges used for linearization with the Eye-One
spectrophotometer.
>
> Carl Schofield

Carl,

Did you use the "grey boost" or whatever it is called in QTR that
brings in a peak of dark grey ink into the Black at 100% ?

I'm using the Wasatch SoftRip free from any default paper setting
for this quad printing. For QTR the recommendation is to use the
matte paper setting of Gimp-print. I wonder whether that
restricts the ink amount already. That shouldn't be necessary as
the quad (Hexa) ink use is very different from the way CcMmYK
printing is done.

With Robert Morrison I am quite sceptic now of spectrometer
readings of the darkest samples in greywedges. He has written
some messages on the subject in March. But I also think that
densitometers have to be checked for matte and gloss readings. It
will depend on the angle of light in the measure head and
possibly in the use on polarisation filters in the measure head.
Similar problems are known in measuring textile colours and with
the "velvet" matte results we get that analogy isn't so far
fetched. In general I think the blacks we get are higher in Dmax
than the spectrometers tell us but not as high as some
densitometers tell us. A friend has an Eye One where I can
compare my samples.

Ernst