An Introduction to Porcelain
Credit for editing on this article goes to Devee Schoenberg, a collector and customer who edits the writing that stems from The National Institute of Health, Bethesda, Maryland.
We have had numerous requests from both established collectors and those who would like to become collectors for information on porcelain in general and Limoges boxes in particular. To satisfy our customers, Elayne plans to write a series of relatively brief articles beginning with this, a somewhat abridged history of porcelain as it pertains to French porcelain.
In The Beginning
To describe French porcelain, one must go back several hundred years to the 14th and 15th centuries. It was during that period of time that porcelain first became known in Europe. China had been making porcelain for many years and when earlier trading routes, established by Marco Polo and Vasco da Gama, transported the goods of the Far East to Europe, porcelain items were brought from China. It was enjoyed mainly by royalty and some of the nobility but was completely out of reach of the masses. It was not until the Dutch became a maritime power in the 16th century and their men of war captured merchant traders coming from the Far East carrying cargoes rich in porcelain, that quantity made it possible for more than just the rich to enjoy the new treasure called "porcelain".
When interest in Chinese porcelain became widespread, the French as well as others, tried vainly to copy it. Because there was no way to determine the composition of this new substance chemically and there were no investigative techniques as we know them today, they proceeded with a lengthy series of experiments, all of which ended in failure. It was recognized that the Chinese porcelain was made similar to maiolica (today known as majolica), a pottery that was thrown on a wheel, and because it was pliable, it had to be fired in a kiln to achieve hardness. The French artisans reasoned that whatever product they succeeded in making had to be manufactured by a similar method.
Chinese porcelain was translucent when held up to a light, as porcelain is today, but at that time, only Chinese porcelain had that quality. Of course, glass was already available and the various artisans experimented with additions of glass to their porcelain to give it the white coloring and translucence. It was a poor substitute and was prepared in an entirely different manner. The ingredients of glass are sand, soda, lime, etc. and they are made liquid and blown; it is only upon cooling that they harden into glass as we know it. The ingredients are never fired at the sustained high temperatures that porcelain requires.
Eventually other countries attempted to make porcelain in the Chinese manner but all of it was with little success and very little of what was made survives today. The "porcelains" of those years are today referred to as "soft paste" porcelain as opposed to porcelain manufactured in the Chinese manner which is referred to as "hard paste" porcelain.
Although porcelain-making continued in France for many years, and some of it, mainly the porcelain made at Sevres, remains among the finest examples of porcelain ever made, it was totally impractical as a product for general use because it could not withstand "real" usage. It was very delicate, very difficult to clean, cracking and breakage in the kiln was enormous. Even the factory at Sevres regarded their exquisite porcelain as a substitute for Chinese porcelain at best.
Making soft paste porcelain in France was discontinued after 1800, but for 31 years both hard and soft paste porcelain were made. For collectors, it is important to be able to discern the differences and for this, there are several tests that are quite easily made. It is recommended that more than one or two tests be made for a true determination:
1. In soft paste porcelain, the base is almost never glazed. If a file can cut into the unglazed porcelain, then it is soft paste. This is not a preferred method because the porcelain can be damaged by too deep a cut or a file mishandled.
2. Air bubbles were frequently trapped in the soft porcelain. These can be seen by holding the porcelain up to a bright light and observing spots that vary in translucency. This can occur, as well, in hard paste porcelain but is infrequent.
3. Firecracks, due to unequal contraction of the porcelain during the cooling process, and warping (sagging out of shape) were both very common in soft paste porcelain but very uncommon in hard paste porcelain. Either can easily be seen. NOTE: Cracks in porcelain should never be referred to as age cracks. Porcelain does not crack with age, rather they develop in the kiln or after manufacture through mishandling.
4. Soft paste porcelain is very porous making it extremely difficult to remove soil or stain if possible at all. Hard paste porcelain can be washed and easily cleaned.
5. The glaze on soft porcelain was sprayed on and left thick residue on the underside of the base of the piece; as well, it tended to pool in hollows and this can easily be seen.. Additionally, most figures were "biscuit" porcelain and left unglazed.
6. Soft porcelain glaze tended to scratch very easily; close inspection reveals these scratches whereas hard past porcelain is extremely difficult to scratch and can only be scratched by something harder than it.
7. Soft porcelain has a very grainy texture, almost like icing before it is thoroughly mixed, which can be seen and felt where there is a chip on the porcelain. This is not the case for hard paste porcelain which chips in the same manner as glass.
Not until 1769 did France start to make hard paste porcelain.
To Be Continued...
NOTE: This is a predigested version of numerous parts of a book written in 1960: