Digital BW, The Print

Jo Brunenberg wrote:

>...
>... month of August (very sunny in the Netherlands where I
>live) I exposed two black-and-white prints to the sunlight in my
roof-window
>on the south. So a rather tough test.

>...
>- The exposed part of the PiezoBW print did not change in the dark gray and
>black areas. There is a very slight fading in the highlights. The exposed
>part is slightly less "greenish". The print still is very acceptable.
>(the slight fading is just visible to the eye and a densitometer does read
a
>minor change).

>- The exposed part of the Lyson print shows a dramatic fading as well as a
>colorshift. ...

The Piezo results sound similar to my experiences.  The greenish tint is
obvious in the two lightest gray inks if they are printed separately.  When
exposed in my florescent light fader, they rather quickly lose the greenish
tint.  I think that is the dye component of the ink fading away.  (See the
Piezo-MIS dot scans in the Message Related Files section of this forum
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/ )

With the black ink, I've had varying results.  Sometimes I get almost no
fading with it.  Other times there is fading.  All I can guess is that some
other factors -- humidity or temperature most likely -- are affecting the
results.  In my latest test the MIS VM black (which I believe is the same as
Piezo black) on EAM only faded 1.4% in 300 hours -- a remarkable
performance, in my view.

Paul
http://www.PaulRoark.com