Baronet covered veg tureen

Bone china

Bone china is a type of porcelain body originally developed in Great Britain in which calcined ox bone, bone ash, is an essential ingredient. It is distinguish by high whiteness, strength and translucency. baronet covered veg tureen may be an example of this process.

The initial use of bone ash in ceramics is credited to Thomas Frye in in the late 1740s in which he used it to introduce a kind of soft-paste porcelain. In As the 18th century drew to a close, Josiah Spode undertook further developments, and subsequently popularized it, by mixing it with china clay, kaolin and China stone to compete with the imported Oriental porcelain.

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

The production of bone china mainly makes use of a two stage firing process where the first "biscuit" is fired without a glaze at 1280°C (2336°F) giving a semitransparent product and then it is glaze, or glost, fired at a lower heat under 1080°C (1976°F). baronet covered veg tureen is probably manufactured using this process.

Soft-paste porcelain

Soft-paste porcelain is a type of porcelain and therefore a ceramic material.

Its origin dates from the initial ventures by European potters to replicate Chinese porcelain by using concoctions of china clay and ground-up glass (aka frit); soapstone and lime were known to have also been added in some compositions. As these early combinations suffered from high pyroplastic collapse, or slumping in the kiln at high temperature, it was uneconomical to produce them. Compounds were later used based on nepheline syenite, quartz, kaolin, feldspars 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 first produced from a concoction of the feldspathic rock petuntse and kaolin fired at very high temperature. It was first made in China in around the 9th century.

The secret of its manufacture was not known in Europe until the early eighteenth century, when Böttger of Meissen, Germany uncovered the formula. Despite attempts to keep it secret, the procedure was taken up by other German ceramic potteries and eventually became widely used throughout Europe.

Hard-paste porcelain can be fired at a range of temperatures to create many different end results. Depending on the firing approach, hard-paste porcelain can resemble earthenware or stoneware. Generally however, it is not necessary to use hard-paste porcelain for these lower temperature ceramics. Hard-paste porcelain can be employed to make porcelain bisque, a hard crystalline product fired at extremely high temperatures in a pressure controlled environment. This technique manufactures a translucid bright white ceramic. Unlike other bisque ceramics, porcelain bisque is almost impermeable by water, making it unnecessary to glaze the body before decorating. Manufacturers such as Lladro, Precious Moments and Hummel employ hard-paste porcelain simply for this reason, this could include baronet covered veg tureen.