The Making of: Porcelain

Porcelain is an ancient ceramic which originated in China. Prized for centuries for its balance of durability and delicacy in comparison to other ceramics, it is made by mixing raw materials, forming the shapes and then vitrified by multiple stages of firing.

The tableware of Chinese royalty, porcelain was first brought to Europe in the 14 th century by Marco Polo. The materials and manufacturing were a closely guarded secret, and it wasn’t until the 18th century that Europeans were able to replicate its characteristic finesse and translucency.

Types of porcelain

There are three types of porcelain: hard paste (or true porcelain), soft paste (or artificial porcelain) and bone china. Ours is hard paste, preferred for its strength, pure white colour and glazed finish.

Hard paste porcelain is made from a mix of kaolin and petunse. Kaolin, also known as China clay, is a soft, silicate mineral which gives porcelain its plasticity and pure white colour. This is combined with feldspar and quartz - essential minerals which give porcelain it characteristic translucency and strength. Soft paste porcelain is weaker than true porcelain. The ingredients vary, but always include clay and rarely the key ingredients to make hard paste. Vitrification can be imitated by firing clay and glass at lower temperatures of around 1200°C, however this produces an inferior product which can be cut with a file, is prone to scratches and marks easily where unglazed on the base. Bone china is made from the same raw ingredients as hard paste porcelain but includes bone ash, which produces a strong yet delicate and translucent product.

The process

The complex production process involves multiple stages, from shaping and firing to glazing and firing and then decoration. The raw porcelain clay is formed in a mould. The ratio of raw ingredients to water to achieve plasticity varies and small changes in the water content can hinder workability; skill and patience are required to achieve the correct consistency and texture. Cups, mugs, plates and bowls are formed in steel moulds while teapots, jugs and serving pieces are slipcast in cast in ceramic moulds. 

Once the object is formed, it is sent for its first ‘biscuit’ firing at 960°C. This hardens the body prior to glazing. Pieces are then glazed and fired again at 1380°C to permanently set the shapes and vitrify the surface, strengthening the structure and rendering the object impermeable. Decoration is hand applied, either hand-painting with lustre or by a transfer. Lustres are hand-painted, the object is fired, the rim or handle may be expertly painted with gold or platinum and then fired again. Different colours need to be fired at a different temperature to achieve the desired effect. The logo backstamp is hand applied as a decal and fired. Once decorated, pieces are sorted and inspected before they are wrapped in tissue and boxed.