Digital BW, The Print

Three PiezoTone test strips reached 300 hours (actually 304 hours) in my
fader Saturday.  They were PiezoTone Selenium (PT-S) on PhotoRag (PR), PT-S
on Epson Archival Matte (EAM), and, for comparison purposes, PiezoTone-Warm
Neutral (PT-WN) on EAM.

In general, there were no surprises.  The PT-S midtones performed extremely
well, with very minimal fade and virtually no midtone warming.

The black ink, however, showed substantial fade and warming, which, with the
cooler PT-S midtones, causes a significant neutral-to-warm cross-over
between 85% and 95%.  Whether this is a problem in your particular prints is
a subjective issue.  However, the resulting prints are not truly "selenium"
tone after the shadow tones have warmed up.  At least with my selenium-toned
silver prints the shadows get increasingly cool, not warm, as the density
increases.

A scan of the test strips can be seen in the Files section of this forum.
The files section is at:
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/

Then following the links:  Files > Ink Sets > PiezoTones.  The file name is
"PT-Sel-PR & EAM PT-NW-EAM 304 Hr Fade.jpg."

Also, as expected, the black ink showed less fading and warming on EAM than
on PhotoRag.  The 100% patch droped from a density of 1.82 to 1.64 on PR; it
dropped from 1.71 to 1.62 on EAM.  The PR 100% patch warmed 0.11 units,
while the EAM 100% patch warmed 0.06 units.  (Warming is measured as the
change in the difference between the cyan and yellow readings.)

Note that these test strips were printed by Martin using a 1280 and CIS.  As
such, they appear to have been totally unaffected by the problems Jon Cone
described in his August 29 "PiezoTone News" posting on the Piezo 3000 forum.
See
http://groups.yahoo.com/group/piezography3000/message/19609

Also cross-posted by Julian at
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/message/18795

The problem Jon described appears to be ink separation caused by the sponge
material used in certain 1280 pre-loaded carts.  They are changeing carts,
but appear also to be changing the dispersion characteristics of the PT-S
inks.  As such, the final PT-S formula may be slightly different than this
one.

The X-Rite densitometer readings are below.

PT-S PR 50%	Control: c=0.69, m=0.71, y=0.72, visual=0.70;
		 304 Hr: c=0.68, m=0.70, y=0.71, visual=0.69;

	 100%	Control: c=1.82, m=1.81, y=1.80, visual=1.82;
		 304 Hr: c=1.61, m=1.68, y=1.70, visual=1.64;

	85% to 95% tone change (change in [c-y]):
		Control: 85% 0.01 unit cool to 95% 0.03 cool;
		304 Hr:  85% c=y (neutral) to 95% 0.08 warm.


PT-S EAM 50% Control: c=0.68, m=0.69, y=0.68, visual=0.69;
		  304 Hr: c=0.68, m=0.69, y=0.69, visual=0.69;

	  100% Control: c=1.71, m=1.72, y=1.72, visual=1.71;
		  304 Hr: c=1.60, m=1.65, y=1.67, visual=1.62;

	85% to 95% tone change (change in [c-y]):
		Control: 85% 0.01 cool to 95% c=y (neutral);
		 304 Hr: 85% 0.01 warm to 95% 0.07 warm.

PT-WN EAM 50% Control: c=0.64, m=0.65, y=0.67, visual=0.65;
		   304 Hr: c=0.66, m=0.67, y=0.70, visual=0.67;

	   100% Control: c=1.70, m=1.72, y=1.74, visual=1.71;
		   304 Hr: c=1.64, m=1.68, y=1.70, visual=1.66;

	85% to 95% tone change (change in [c-y]):
		Control: 85% 0.02 warm to 95% 0.02 warm
		 304 Hr: 85% 0.03 warm to 95% 0.06 warm.


Paul
http://www.PaulRoark.com