Digital BW, The Print

I think that Wilhelm has come to the conclusion long ago (and he 
deservs credit for it) that unlike analogue silver media, inkjet prints 
of All Kinds need to be stored in one of three ways 1. behind 
glass/plexi 2.if not glass then sprayed with an acrylic sealer 3. dark 
storage out of the reach of ozone. That is just where the technology is 
now. To me it is not prudent to ignore thatin these tests, with any 
inkjet media on any substrate unless permanence is not a concern. The 
German tests that Ernst quotes are not following that recomendation but 
do genearlly support Wilhelm's "bare bulb" results. Think about it the 
degree and intensity of ozone in the environment is so variable from 
location to location that it is almost impossible to account for in 
universal way.

Dmax

Could it be said that any black and white print that reflects a dmax of 
over say 1.69 or so on Photorag has something more than pure pigment in 
it? My dmax with Piezography K7 is 1.68 with an amazingly smooth 
result. I wouldn't consider it fair to compare that with the older 
generation quads run run out of an icc profile situation on a small 
printer. Studio Print and the Portfolio Black are a different story. We 
expect each generation to be an improvement. That is the whole point.

John




> The Wilhelm B&W results however give a much higher lifetime
> on bare bulb testing: >200 years but still >100 years for
> ozone. I think Wilhelm's ozone test is only telling
> something when there's something utterly wrong with the
> paper/ink combo I guess and not all that fails then is
> published either.  Or IE's ozone test is too harsh. The
> Epson 2400 inks show more problems at least.
> 
> http://digitalkamera.image-
engineering.de/downloads/Haltbarkeit_Papiere-Cofo.pdf
> bottom of the pages.
>