Florentine black and gold bread butter plate

Bone china

Bone china is a kind of porcelain body first used in the UK in which calcined ox bone, bone ash, is an important ingredient. It is differentiated by supreme whiteness, translucency and strength. florentine black and gold bread & butter plate may be an example of this process.

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

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

Bone china production commonly involves 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 glost, or glaze, fired at a lower setting less than 1080°C (1976°F). florentine black and gold bread & butter plate is probably made using this process.

Soft-paste porcelain

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

Its origin dates from the early trials by European potters to replicate Chinese porcelain by employing concoctions of china clay and ground-up glass (also known as frit); soapstone and lime were known to have also been employed in some compounds. As these first combinations were prone to high pyroplastic collapse, or slumping in the oven at raised temperature, they were uneconomic to manufacture. Formulations were later developed based on kaolin, quartz, feldspars, nepheline syenite and other feldspathic rocks. These were technically superior and are still in production to the present day.

Hard-paste porcelain

Hard-paste porcelain is a hard, dense ceramic that was initially produced from a formulation of the feldspathic rock petuntse and kaolin fired at very high temperature. It was first manufactured 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 discovered the formula. Regardless of attempts to keep it secret, the procedure was used by other German ceramic manufacturers and eventually became well used throughout Europe.

Hard-paste porcelain is fired at a range of temperatures to make many different end results. Depending on the firing method, hard-paste porcelain can be made to resemble stoneware or earthenware. Generally however, it is not necessary to employ hard-paste porcelain for such lower temperature ceramics. Hard-paste porcelain can be employed to create porcelain bisque, a hard crystalline product fired at extremely high temperatures in a pressure controlled environment. This approach generates 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 Precious Moments, Hummel and Lladro utilize hard-paste porcelain exactly for this reason, this could include florentine black and gold bread & butter plate.