YInMn Blue and the furnace that made a new blue

An experiment that went somewhere else

In 2009 Andrew Smith, a graduate student in Mas Subramanian's group in the chemistry department at Oregon State University, was exploring the electronic properties of manganese oxide. The team was hunting for new materials for electronics, not for colours. Smith mixed oxides of yttrium, indium and manganese and heated them to around 1,200°C. What came out of the furnace was a brilliant blue compound that nobody had made before.¹²

Subramanian, who had spent years in industrial research at DuPont, recognised that he was looking at a possible pigment and filed a patent disclosure.³ The fact that the compound had formed at such a high temperature suggested it would be very stable, which is exactly what you want from a pigment.¹ The group published the result in the Journal of the American Chemical Society at the end of 2009 under the title "Mn3+ in Trigonal Bipyramidal Coordination: A New Blue Chromophore".³

They named it after its elements. Yttrium, indium and manganese give YInMn, usually said "yin-min".

Why it is blue

The paper's title holds the explanation. In YInMn the manganese atoms carry a 3+ charge and sit in an unusual arrangement, each surrounded by five oxygen atoms in the shape of a trigonal bipyramid, like two triangular pyramids joined at the base. That geometry changes the way the manganese absorbs light, so the material swallows red and green wavelengths and reflects a strong blue. Changing the ratio of indium to manganese shifts the shade, and the bluest version is close to standard cobalt blue in colour.³ The same research line has since produced related greens, purples and oranges.³

Oregon State and the press have described it as the first new blue pigment in about 200 years. The comparison is with cobalt blue, the last inorganic blue to be manufactured commercially before it, which was discovered in 1802 and first produced in France in 1807.⁴ Subramanian put the gap plainly in 2016: "People have been looking for a good, durable blue color for a couple of centuries."²

What makes it useful

The first selling point is durability. YInMn does not fade, keeps its colour in oil and in water, and resists acids such as nitric acid.³ When the Shepherd Color Company tested it, it found better ultraviolet absorbance and better results in outdoor weathering and heat build-up tests than cobalt blue.¹ It is also described as non-toxic, which cobalt blue cannot claim, since cobalt is poisonous in large quantities.³⁴

The second is heat. YInMn reflects a large share of near-infrared light, much more than cobalt blue does.¹⁴ Near-infrared is the invisible part of sunlight that warms surfaces, so a coating that reflects it stays cooler. That makes YInMn a candidate "cool pigment" for roofs and exteriors, where a cooler surface can mean lower cooling costs.¹ In 2016 the chip maker AMD said it would use the pigment on some of its professional graphics cards for the same reason.³ As happens often in the history of colour, industry was interested before artists could get hold of it.

The slow road to the paint tube

Oregon State was granted a US patent in 2012. Shepherd, a pigment maker in Ohio, signed a non-disclosure agreement, tested the material and licensed the patent, taking the commercial rights in 2016.¹² In the United States a new chemical then has to pass the Environmental Protection Agency. The EPA approved YInMn for industrial coatings and plastics in September 2017 and for wider commercial use, including artists' materials, in May 2020. It was approved as finished paint, not as a dry powder.⁴⁵

Before that, the colour reached the public in a roundabout way. In 2017 Crayola retired its yellow Dandelion crayon and replaced it with a blue inspired by YInMn, named Bluetiful after a public vote. The crayon contains no YInMn.⁶³

Real YInMn paint followed in small quantities. The Australian maker Derivan had experimented with it in its Matisse acrylics as early as 2016 and sells it as Oregon Blue.³⁵ By early 2021 Golden Artist Colors in New York offered it through its custom lab, and Kremer Pigmente in Germany had its own products.⁵

Why it costs so much

When the Italian Art Store in Maine began selling Derivan's YInMn in the US, a 40ml tube cost $179.40, about six times its most expensive acrylic.⁴⁵ The reasons are mundane. The pigment is made from rare earth elements, indium among them, scaling up from a lab that made a few grams at a time to a factory making hundreds of kilograms is hard, and every step needs regulatory approval.⁵ Several paint makers decided it was not worth it. Turner, Holbein and Kusakabe in Japan tested it and passed, and Gamblin told Artnet in 2021 that the cost was too high for the benefit to painters.⁵

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1. Oregon State University College of Science, The story of YInMn Blue, Oregon State University, 2023.
2. Hyperallergic, Meet YInMn, the first new blue pigment in two centuries, Hyperallergic.
3. Wikipedia, YInMn Blue, Wikimedia Foundation.
4. Smithsonian Magazine, For the first time in 200 years, a new blue pigment is up for sale, Smithsonian, 2021.
5. Artnet News, YInMn Blue comes to market, Artnet, 2021.
6. Oregon State University College of Science, Bluetiful: Crayola names new YInMn Blue inspired crayon, Oregon State University, 2017.