Digital BW, The Print

...

>Given that carbon is not non-reactive, grinding it to a 
>superfine level enormously increases the surface to volume 
>ratio and may, therefore make it much more physically 
>(not chemically) reactive, no?

Probably.

I've found the information at http://www.handprint.com/HP/WCL/pigmt3.html to
be extremely useful.  The tables include information on particle sizes and
specific gravities, attributes that are very significant to our inks.

Note how finely ground the carbon black is that watercolor artists use.  I
think these people, who have been concerned with lightfastness for a long
time and have much more flexibility in materials than we do, might have
useful information relative to our field.  If is it true that they use
carbon ground to such a fine size, then it suggests to me that the material
is tough enough that we're not being too negatively affected by the sizes
needed for our medium.

Paul
www.PaulRoark.com