The Artist's Road Painting the World's Beautiful Places

 Getting Blue

Perspectives from The Artist's Road

   Where would painting be without the color blue? It is so easy to obtain artist paints of any hue these days that we forget that in the time of both Michelangelo and Titian, a pure, vibrant blue pigment could only be made by laboriously cooking and hand-grinding a stone of lapis lazuli into a fine powder, and then adding oils and binders to make it into a suitable paint. Called “oltramarino”, it was made from surpar, the very finest lapis lazuli from Afghanistan. It was the most expensive paint material in the world, and so not always readily available. In those days, it was not uncommon that a commissioned painting would have to remain incomplete until the expensive surpar could be furnished by the wealthy patron.
 
   It was not until another blue was discovered that artists had any other choice. This new pigment, nearly as valuable to artists as oltramarino, originally came from Persia, now Iran, and in English was called "cobalt", a corruption of the German "kobald", or gremlin. Discovered by silver miners, it was hated because it attracts deadly arsenic. It also has a propensity to change colors upon heating, and so was used in invisible inks. In high-temperature uses, however, it is very stable and produces a brilliant deep sky blue color. Thus, it became a highly-prized glaze used by the Persians on their tile and the Chinese on their porcelain ware.

   Although it had been used in impure forms in pigments since the 1500s, it wasn’t made into a pure artist’s pigment until the nineteenth century, by a scientist named Louis-Jacques Thenard. It was and still is, an expensive pigment to use. But why? Modern mining operations and efficient industrial processing should have made cobalt relatively inexpensive by now. Part of the answer is that the U.S. has no domestic supply of the metal and imports 20% of the world production each year. The main reason, though, is that cobalt is far more in demand for industrial uses than artistic ones.
 
   In a chart of pigment information contained in James Gurney’s book, Color and Light, we noticed an interesting remark after “cobalt blue”. It says, “Expensive due to use on jet turbine blades.” This prompted a little more research which revealed cobalt’s true story. From a company mining and selling cobalt called Idaho Cobalt, we found a confirmation of the other more extensive uses of cobalt:  “Cobalt is an essential alloying element in high temperature super alloys used for casting airfoils and structural parts in jet turbine engines. . . Substitution for cobalt in jet engine castings will probably not occur and cannot be considered as a meaningful solution to the cobalt supply problem."

   Cobalt is considered a “strategic metal” by the U.S. Government. Its uses include solar panels, wind turbines, rare earth magnets, communication satellites, geothermal and hydrogen energy production and storage, cell phones, tablets, laptops, hard disc drives, vitamins, prosthetics, and cancer treatment, just to name a very few applications.
 
   Ironically, this demand may eventually drive the price of cobalt to the point where we come full circle back to the days of Michelangelo, where artists will have to either forego the use of cobalt in their paintings or do as he did and ask their affluent patrons to supply it for them!