Digital BW, The Print

The fade test of the PiezoTone NW, FS standard, and FS-N inksets on Photo
Rag has reached 600 hours.  This is the end of the test for now, as I have
put PiezoTone Selenium test strips in the fader to see how they do.

A scan of the control and 600 hour fade test strips is in the files section
of the forum in folder:

Files > Ink Sets > PiezoTones > PiezoTone vs MIS-FS >
WN-PiezoTone 600 hr fade test.

The files section is at
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/

In addition to a Jpeg of the scanned test strips, there is a graph of the
fading and warming results over time.  So, you can see what the relative
fade and warm rates look like.

The standout performance was the PT-NW midtone.  At the 50% patch, the PT
faded only 0.01 density units (measured by an X-Rite with maximum
sensitivity/resolution of 0.01).  It did not warm at all.  (I measure
warming as the change in the difference between the cyan and yellow
readings.)  This is a very impressive result.

By comparison, the FS-N 50% warmed 0.02 units, and the FS (standard) warmed
0.07 units.  The FS & FS-N 50% patches faded 0.12 units.

The ink that faded and warmed the most was the PT black.  By 600 hours it
was less black than the FS blacks, having faded 0.20 units compared to the
average FS-K fade of 0.085 units.  The PT black was fading at a high rate
between 500 and 600 hours, with a (negative) slope of more than 4 times the
average FS black fade slope at that same point.

The PT-K (100% patch) had warmed 0.13 units by 600 hours and was still
warming at a relatively high rate.  The average warming of the FS Ks was
0.05 units.  The rate of warming for the PT-K between 500 & 600 hours was
about twice that of the FS-K average at that same point.

The oddest result was the FS and FS-N blacks performed differently, and they
are supposed to be the same ink.  For example, the FS standard test strip
black warmed over twice that of the FS black on the FS-N test strip; it also
faded slightly more.  Perhaps there is some midtone ink in the 100% patch
that is affecting the blacks, or perhaps there were other factors such as
ink lot or even humidity differences when the test strips were printed.

Note that these fade results are for PhotoRag.  My limited previous
experience with Hahnemuhle paper suggested that pigmented black inks fade
substantially more on the Hahnemuhle paper than on Epson Archival Matte.
For example, the PhotoRag test strips with the FS inks, at the 100% patch,
in the current test faded, on average, 0.085 units.  On the other hand, in
my last test of a VM black (which is the same as FS black) on EAM, the 100%
patch had faded, on average, only 0.015 units after 600 hours.  Although
these were two different tests, the difference is so dramatic that it
suggests the paper differences could be very significant.

With the just-started PT-selenium test, I have put both a PhotoRag and EAM
test strip in the fader.

Paul
http://www.PaulRoark.com