Cerulean Blue: Mixed metal oxide from the early 19th century with an important place on the mineral palette because blues are rarely shifted to the cool, green side like this one. It replaced azurite. Very muted in its tint so it is most valuable as a pure hue.
Pigment: Oxides of cobalt & tin (PB 35), Vehicle: Alkali refined linseed oil
Lightfastness I, Series 6, OPAQUE