Digital BW, The Print

It looks like Epson has updated the paper & media section of their site.

http://www.epson.com/northamerica.html
Click on "Paper & Media" under Products.

They now have individual web pages for each paper with links in many cases
to a pdf "fact sheet" and permanence ratings from Wilhelm.

Much more organized and easier to follow than before.

I also stumbled across a technical brief on Epson Archival Inks at
http://files.support.epson.com/pdf/pro55_/pro55_ta.pdf
where they explain a little about the differences between their archival
pigment inks and conventional pigment inks.  I don't know how old this
information is, but at the Epson Print Academy, Vincent Versace displayed
the same slide portraying Epson's MicroCrystal Encapsulation Technology
while talking about UltraChrome inks.

To view all three inkjet related tech briefs, look here:
http://files.support.epson.com/pdf/600q__/600q__ti.pdf

Finally, looking at the MSDS sheets for the 2200 UltraChrome inks, it
appears a major difference between Photo Black and Matte Black is that Photo
Black contains carbon black and more glycerols.  Matte Black has no carbon
black, but contains more proprietary dyes and pigments, more proprietary
ogranic materials, and less Glycerols.

Interestingly, the carbon black in the Photo Black ink is listed as a
carcinogen with excessive exposure, although the safety sheet says that
emission to air during normal printing has not been found.

It looks like UltraChrome Photo Black is a closer relative to Epson Archival
Black than Matte Black is.  Archival Black also contains carbon black, but
has less proprietary dyes and pigments, more proprietary organic materials,
and less glycerols.