Ok time to dismiss another classic pigment! I love Cobalt Violet there is something so special in it's delicacy, however its very low tinting power means it can disappear in mixes and being a Series 5/6 paint it is an expensive business using it.
Now we have Dioxazine Violet...a Series 2 paint with exceptional tinting power, a crumb of this into cadmium yellow will take the chroma right down, whereas with cobalt violet you would have used half a tube and ended up with something quite brown!
The masstone is a very deep blue purple, it's transparency lends itself to glazing, screaming cool shadows. As a secondary colour, you can of course mix violet from red and blue but you will never get anything as clean, powerful and transparent as this. Sometimes known as carbazole violet.
Pigment - PV23. Dioxazine
Vehicle - Linseed Oil, Consistency - Buttery