Biltmore

Bone china

Bone china is a type of porcelain body initially developed in England in which calcined ox bone, bone ash, is a critical ingredient. It is differentiated by extremely high whiteness, translucency and strength. biltmore may be an example of this procedure.

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

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

The manufacture of bone china normally involves a 2 stage firing process where the first "biscuit" is fired without a glaze at 1280°C (2336°F) giving a translucent product and then it is glaze, or glost, fired at a lower heat under 1080°C (1976°F). biltmore is probably manufactured using this technique.

Soft-paste porcelain

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

Its history dates from the first pursuits by potters from Europe to copy Chinese porcelain by employing compositions of china clay and ground-up glass (otherwise known as frit); soapstone and lime were known to have also been used in some concoctions. As these initial formulations were prone to high pyroplastic collapse, or slumping in the oven at high temperature, they were not economical to manufacture. Mixtures were later used based on nepheline syenite, feldspars, kaolin, quartz and other feldspathic rocks. These were technically superior and continue in production to the present day.

Hard-paste porcelain

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

The secret of its manufacture was not known in Europe until the early eighteenth century, when Böttger of Meissen, Germany found the formula. Despite attempts to keep it secret, the process spread to other German ceramic potteries and eventually became widely used throughout the length and breadth of Europe.

Hard-paste porcelain is fired at a range of temperatures to manufacture many individual end results. Depending on the firing process, hard-paste porcelain can be made to resemble stoneware or earthenware. But most of the time, it is unnecessary to use hard-paste porcelain for such 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 method makes a semiopaque bright white ceramic. Unlike other bisque ceramics, porcelain bisque is almost inpenetrable by water, therefore it becomes unnecessary to glaze the body before decorating. Manufacturers such as Hummel, Lladro and Precious Moments utilize hard-paste porcelain exactly for this reason, this could include biltmore.