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.
Jasperware
The earliest jasper was stained throughout, which is known as "solid," but before long most items were coloured only on the surface; these are known as "dipped" or "dip". Dipping was first used in 1777, Wedgwood writing that "the Cobalt @ 36s. per lb, which being too dear to mix with the clay of the whole grounds". By 1829 production in jasper had virtually ceased, but in 1844 production resumed making dipped wares. Solid jasper was not manufactured again until 1860. Early dark blue was often made by dipping a body made from the solid light blue. In the best early pieces the relief work was gone over, including some undercutting, by lapidaries.