Hartington plate 6 1 2 inch

Bone china

Bone china is a type of porcelain body initially produced in Great Britain in which calcined ox bone, bone ash, is an essential constituent. It is characterized by extremely high whiteness, strength and translucency. hartington plate 6 1/2 inch may be an example of this process.

The first use of bone ash in ceramics is assigned to Thomas Frye in 1748 in which he used it to develop a kind of soft-paste porcelain. In At the close of the eighteenth century, Josiah Spode undertook further developments, and duly popularised it, by combining it with china clay, kaolin and China stone to compete with the imported Oriental porcelain.

The initial elementary formula of six parts bone ash, four parts china stone, and three and a half parts china clay is still the standard English body.

Bone china production usually uses a 2 stage firing where the initial "biscuit" is fired without a glaze at 1280°C (2336°F) giving a semitransparent product and then it is glost, or glaze, fired at a lower heat below 1080°C (1976°F). hartington plate 6 1/2 inch is probably made using this method.

Soft-paste porcelain

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

Its history dates from the early struggles by European potters to imitate Chinese porcelain by employing compositions of china clay and ground-up glass (otherwise known as frit); soapstone and lime were also known to have been added in some combinations. As these initial mixtures suffered from high pyroplastic deformation, or slumping in the kiln at high temperature, they were not economical to manufacture. Concoctions were later used based on kaolin, quartz, nepheline syenite, feldspars and other feldspathic rocks. These were technically superior and are still in production today.

Hard-paste porcelain

Hard-paste porcelain is a hard, dense ceramic that was first manufactured from a composition of the feldspathic rock petuntse and kaolin fired at very high temperature. It was first produced in China in around the 9th century.

The secret of its manufacture was unknown in Europe until the early 1700s, when Böttger of Meissen, Germany discovered the formula. Regardless of attempts to keep it secret, the procedure spread to other German ceramic manufacturers and eventually became used throughout Europe.

Hard-paste porcelain is known to be fired at a range of temperatures to make a myriad of individual end results. Depending on the firing process, hard-paste porcelain can resemble earthenware or stoneware. Generally however, it is unnecessary to employ hard-paste porcelain for these lower temperature ceramics. Hard-paste porcelain can be used to manufacture porcelain bisque, a hard crystalline material fired at extremely high temperatures in a pressure controlled environment. This technique gives birth to a translucid bright white ceramic. Unlike other bisque ceramics, porcelain bisque is almost impermeable by water, therefore it becomes unnecessary to glaze the body before painting. Manufacturers such as Precious Moments, Hummel and Lladro utilize hard-paste porcelain exactly for this reason, this could include hartington plate 6 1/2 inch.