YInMn Blue (PB86) is the first inorganic blue in over 200 years. It was discovered by chemist Dr. Mas Subramanian and his team in 2009 at Oregon State University. This pigment has since been exclusively licensed to and brought to commercialization by The Shepherd Color Company.
I was interested to check out this colour but it's incredibly expensive. There are many sellers on Etsy selling their handmade paint and half pans can cost around US $45 - $80. The price varies wildly. This is even more expensive than Lapis Lazuli.
The half pan that I have is a sample from Alina Gallo. It's one of the colours included in the watercolour signature set 2 that she's selling. By the way, her products are always out of stock because they only stock once a month. At the time of this review, they don't sell YInMn Blue separately.
According Golden Artist Colours, the colour space of YInMn Blue is between Cobalt Blue Deep (PB74) and Ultramarine Blue (PB29). I made the mistake of using Cobalt Blue instead of Cobalt Blue Deep in the swatch above.
YInMn Blue is a granulating transparent blue. The tinting strength is good meaning you can achieve intensity with a bit of paint. I wasn't able to test the lightfastness of the paint though.
This is how YInMn Blue (PB86) compares to Cobalt Blue Deep (PB74). PB74, as the name suggest, has a deeper blue. I probably won't be able to tell the two apart without a side by side comparison. By the way, Cobalt Blue Deep is one of the most granulating watercolour paint.
Here's a sketch I painted with YInMn Blue.
YInMn Blue looks very similar to Cobalt Blue Deep and behaves the same. So there's no real reason to buy YInMn Blue when Cobalt Blue Deep is cheaper.
The intense granulating is lovely.
The green here was mixed with Nickel Azo Yellow PY150. This green looks like Sap Green or a green you can mix with Ultramarine.
You can get some nice colour separation with various mixtures.
YInMn Blue is a beautiful blue but since it looks so similar to Cobalt Blue Deep, there's no real reason to buy this over the latter especially when YInMn Blue is so expensive. And there are not many companies currently selling this colour commercially except for the few sellers on Etsy, and from Alina Gallo and Kremer Pigments.
To find out more about YInMn Blue, check out these links:
Artist Problems - YInMn Blue, What's the BFD?
Dr Oto Kano swatches