Just found a great supplier of all things pigment. http://www.kremerpigments.com/shopus/index.php?lang=ENG
There are a LOT of interesting pigments on this website, which should appeal to anyone who's into carbon or gum printing. The nice thing is that they appear to be easily bought, that is, like internet buying should be! (not some roundabout rigmarole of requesting a quote, meeting minimum quantities, requesting a sample, etc.)
Here are the UltraStable pigments in aqueous dispersions. They can also be bought raw and as studio pigments, but this just seemed too convenient not to mention.
PB 15:3 , PR 122 , PY 184