Bisque porcelain or biscuit porcelain, takes its name from it's first or initial firing, when the brittle porcelain could be snapped off like a biscuit.
Bisque porcelain is also widely known as "biscuit ware", unglazed ware and more popularly as "parian" ware. All bisque or parian porcelain is unglazed and in Victorian times was admired for its sculptural qualities. The name "Parian" is in fact attributed to Thomas Minton, the famous 19th century English potter, who coined the name Parian after Paros, the Greek island that quarried much of the pure white sculptural marble used in studios. Of course, the originator of porcelain was China, including unglazed white bisque porcelain, known to the Chinese potters as "Fan Ts'u". China was, before the early 18th century, the only producer of porcelain in the world and this is commemorated by the standard name we give to porcelain - "China".
When porcelain receives its first firing, it is porous. It is then glazed and refired. This second firing causes the glaze to fuse with the porous shape and become vitrified, or "glass-like". From this "glazed in the white" state, it is then moved to the decorating department to be painted by skilful porcelain painters, or to be transfer printed.
At the finish of this decorating process, the shape is then refired to fix the coloured enamels. If gilding is to be applied, the shape is fired yet again with each firing at a lower temperature than the last, the heat being gradually reduced. In the production of bisque porcelain, the porcelain is left in the white and unglazed.
Ceramic glazes have an enormous benefit to porcelain manufacturers as glazes hide faults. With bisque, this helpful element is missing and quality is entirely dependent on detailed modeling and production control.
We illustrate a pair of Bisque lamps, described as -
A fine pair of, English, high Victorian, or possibly, American made, slip cast, bisque lamps. Bisque, also known as "biscuit", is unglazed porcelain which has been fired only once.
The lamps of formal neo classic style with a deep cream colour. The upper section of the lamps, moulded as formal acanthus compositions and the central urn shapes moulded with evenly spaced swags supported by tied ribbons. The centres of the urns decorated with large loose bouquets of garden flowers and foliage supported by a suspended tie.
The urn shaped lamps on short circular socles, the rims dragooned and standing on square shaped plinths.
Bisque, with a new creamy colour was revived in 1846 and again at the close of the 19th century. It has a range of colours, from white to cream and was also known as "Parian", a reference to the white marble from the Greek island of Paros, much sought by sculptors. Bisque was much favored throughout the Victorian period, due to its rather sculptured appearance.
These are very stylish pair of late Victorian lamps.
Circa 1890 Overall height (including shades)20 "/50 cm
Although we still retain the name "bisque porcelain", modern production methods now produce a hard, durable, ceramic body, without the brittleness of very earlier bisque which required glazing to stabilize the shape.
In Europe, pure white, bisque porcelain, just like a ballerina, stepped onto centre stage in the 1750's with the production of stunning portrait busts and figure groups in dazzling, white marble look-a-like.
At the Vincennes factory, a beautiful series of children, modelled from sketches by Boucher and modelled by Blondeau were produced with other mid 18th century factories, like Sevres and Mennecy, producing figure subjects of sublime quality.
In 18th century England, the Derby factory produced finely detailed figures in undecorated bisque. With English figures being conventionally decorated in colour, these figures must have looked outstanding.
The English 18th century highpoint came in 1774, with Josiah Wedgwood's discovery of jasper. Jasper is a fine grained, unglazed stoneware, now so well recognised as to be seen as synonymous with the name of Wedgwood.
Jasper was copied by the French at Sevres, in biscuit porcelain and at other French and German factories. By the end of the 18th century, as usual, tastes changed and the unadorned, neo classic styles predominated. Bisque porcelain reached new heights of refinement with elegant Regency styles.
Bisque library busts, Wedgwood unglazed white jasper and elegant French and English bisque models. Bisque, with a new creamy colour was reintroduced by Copeland in Staffordshire in 1846 and was soon taken up by other English and American makers.
And now, for the technical part! The production of a bisque porcelain figure, or lamp base, begins with the eye of the designer, who, with sketch pad and pencil, outlines the design idea. This idea, will naturally, be framed by the contemporary styles of the time.
Bisque porcelain, like all complex ceramic shapes, is cast or slip moulded. Slip is liquid slurry, which is comprised of potters' clay mixed with water to a semi liquid creamy state which is literally poured into preformed plaster of Paris moulds to take shape.
Slip is the raw material behind the beautiful porcelains we see. This liquid porcelain is a mixture of kaolin, feldspar and finely ground flint. Kaolin is naturally occurring, very fine clay with a high percentage of silicate.
Feldspar is a crystalline mineral, also with a high level silicate content and the finely ground flint is a hard quartz. This lists only the primary content of this porcelain mixture, which was refined and developed over hundreds of years.
The chemistry is much more complex with potassium, sodium and calcium contributing to the finished product. Both pottery and porcelain are made by pouring the slip into plaster moulds, the plaster absorbing water from the slip, causing a firm layer to form, the surplus then being poured off.
It is interesting to note that the tradition of slip casting with plaster of Paris, preshaped moulds is not new, the process being introduced in England in about 1745, reputedly by a potter named Ralph Daniels of Cobridge.
When the remaining slip has become cheese hard or sometimes referred to as "leather hard", the plaster moulds are removed and the slip cast shapes assembled to produce the desired design.
Traditionally, this assembly function was performed by a member of the staff called "the repairer". It was his job to remove all seams and smooth out any traces of the mould. This finishing process is much the same as today with slip being used to act as an adhesive. When the assembly is completed, the shapes are thoroughly air dried to allow the pieces to dry.
The now finished shape is sent to the kiln for firing. Some things never change and the basic production of this elegant porcelain it would seem is one of them.
And remember, a good lamp, used to be hard to find!
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