|From the Rembrandt Website, Cobalt Blue!|
A nice little write up on the artist's pigment cobalt blue. It's a toxic pigment and one does have to use caution when working with it. Any WoW gamer will find the reference to "kobolds" amusing - that is how this mineral pigment first got it's name. The only inaccuracy is that at the end of the article it says that cobalt blue is opaque but it isn't. You can read the article here.