Digital BW, The Print

Robert wrote:

>...  The beauty of Piezo (or straight MIS) is
>that all the ink is pure black. ...

Actually, I think one of the problems with Piezo is that there is green-blue
dye in it.  I think Cone should have used pigments to color the inkset.

Also, all of the pigments are, I'm told, carbon at their core, but the
action is with the colorant that coats the carbon.  Even the black ink has a
black colorant around the carbon because the raw carbon is a warm brown, not
a deep black.

So, among black pigments, I suspect there is a difference in fading
depending, in part, on the quality of the black colorant that is used.  Of
the blacks I've tested, the Piezo and MIS VM blacks appear to be the same
and the best.  However, in some tests I do see significant fading & warming
even with these blacks.  I think they are susceptible to heat and
humidity -- perhaps in combination.

Paul