Cobalt blue
Cobalt blue in impure forms had long been used in Chinese porcelain, but it was independently discovered as a pure alumina-based pigment by Louis Jacques Thénard in 1802. Commercial production began in France in 1807. The first recorded use of "cobalt blue" as a color name in English was in 1777. The leading world manufacturer of cobalt blue in the 19th century was Benjamin Wegner's Norwegian company Blaafarveværket ("blue colour works" in Dano-Norwegian). Germany was also famous for production, especially the blue colour works ("Blaufarbenwerke") in the Ore Mountains of Saxony.
International Klein Blue
Although Klein had worked with blue extensively in his earlier career, it was not until 1958 that he used it as the central component of a piece (the color effectively becoming the art). Klein embarked on a series of monochromatic works using IKB as the central theme. These included performance art where Klein painted models' naked bodies and had them walk, roll and sprawl upon blank canvases as well as more conventional single-color canvases. Six sculptures by Klein in the Musiktheater im Revier, Gelsenkirchen, Germany, are executed in IKB.