Digital BW, The Print

I know this is a naive question, and one I should know the answer to, but what actually is 
in UltraChrome ink? Are they a hybred inkset composed of some dye and mostly pigment, 
or what? I think Nash Editions was going to call them pigment prints and I was about to do 
the same, but I'm wondering if that is really a good idea? I don't like do deceive people if I 
know better.

John