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.
Blue and white pottery
The origin of this decorative style is thought to lie in Iraq, when craftsmen in Basra sought to imitate imported white Chinese stoneware with their own tin-glazed, white pottery and added decorative motifs in blue glazes that had been developed by preexisting Mesopotamian cultures. Such Abbasid-era "blue and white" pieces have been found in present-day Iraq dating to the 9th century A.D., decades after the opening of a direct sea route from Iraq to China. Later, in China, a style of decoration based on sinuous plant forms spreading across the object was perfected and most commonly used. Blue and white decoration first became widely used in Chinese porcelain in the 14th century, after the cobalt pigment for the blue began to be imported from Persia. It was widely exported, and inspired imitative wares in Islamic ceramics, and in Japan, and later European tin-glazed earthenware such as Delftware and after the techniques were discovered in the 18th century, European porcelain. Blue and white pottery in all of these traditions continues to be produced, most of it copying earlier styles.