Baroness

Bone china

Bone china is a kind of porcelain body first produced in England in which calcined ox bone, bone ash, is a major constituent. It is characterized by brilliant whiteness, translucency and strength. baroness may be an example of this procedure.

The initial use of bone ash in ceramics is credited to Thomas Frye in 1748 in which he used it to make a type of soft-paste porcelain. In In the late eighteenth century, Josiah Spode undertook further developments, and duly made it popular, by mixing it with China stone, kaolin and china clay to compete against the imported Oriental porcelain.

The original elemental recipe of four parts china stone, three and a half parts china clay, and six parts bone ash remains the standard English body.

The production of bone china mostly employs a two stage firing where the first "biscuit" is fired without a glaze at 1280°C (2336°F) giving a translucid product and then it is glost, or glaze, fired at a lower heat under 1080°C (1976°F). baroness is probably manufactured using this method.

Soft-paste porcelain

Soft-paste porcelain is a kind of porcelain and consequently a ceramic product.

Its origin dates from the initial undertakings by European potters to replicate Chinese porcelain by using mixtures of china clay and ground-up glass (aka frit); soapstone and lime were also known to have been employed in some compounds. As these first concoctions were prone to high pyroplastic collapse, or slumping in the oven at raised temperature, they were uneconomic to manufacture. Compositions were later used based on feldspars, nepheline syenite, quartz, kaolin and other feldspathic rocks. These were technically superior and continue in production to this day.

Hard-paste porcelain

Hard-paste porcelain is a hard, dense ceramic that was initially produced from a mixture of the feldspathic rock petuntse and kaolin fired at extremely high temperature. It was first made in China in about the ninth century.

The secret of its manufacture was unknown in Europe until the early 1700s, when Böttger of Meissen, Germany uncovered the formula. In spite of attempts to keep it secret, the process was taken up by other German ceramic factories and finally became used throughout the whole of Europe.

Hard-paste porcelain is known to be fired at a range of temperatures to make a myriad of different end results. Depending on the firing technique, hard-paste porcelain can be manufactured to resemble earthenware or stoneware. Generally however, it is unnecessary to make use of hard-paste porcelain for these lower temperature ceramics. Hard-paste porcelain can be used to create porcelain bisque, a hard crystalline material fired at very high temperatures in a pressure controlled environment. This process manufactures a semiopaque bright white ceramic. Unlike other bisque ceramics, porcelain bisque is almost inpenetrable by water, making it unnecessary to glaze the body before painting. Manufacturers such as Hummel, Lladro and Precious Moments utilize hard-paste porcelain just for this reason, this could include baroness.