This color is as deep as the sea- a blue worthy of exploration. A deep indigo which is excellent on its own or for complementary color mixing. Compared to Ultramarine, Indanthrone is often every so slightly muted, as one would think of Indigo often having just a slight low-saturation note amid its brightness. It is usually a bit darker than ultramarine, and is a lovely color for landscape work.
We were very surprised to learn that it may actually be carcinogenic. Sometimes called Anthraquinone Blue, this color has not been specifically tested for toxicity, but it bears a chemical similarity to other anthraquinones which are believed to be carcinogenic. Please see Monona Rossol's research research for more information. This color leans more toward violet than phthalo blue and is well suited to moody marine landscapes-- overall a gorgeous color but handle with appropriate care.
