This is probably one of the questions that comes up most often from my clients : How do I recognize porcelain from ironstone ?
"After years of antiquing and tons of books read on the subject, I propose you a little recap' to go to the essential and understand everything in a few minutes."
Ceramics is an ancestral art. The earth is the first material that man sought to work in the Neolithic and has never stopped since. Terracotta objects are a true testimony of our way of life through time and are valuable remains for historians.
A point of vocabulary
First of all, there are the Arts of Fire which include the work of ceramics, glass and metal.
Ceramics is the generic term to use if you are not sure of the material you have in your hands, it means all the objects made in earth (faience, ironstone, porcelain, etc. all are ceramic).
In this large family, there are many categories, their main difference being the mixture of soil that makes them up. The most used are clay, kaolin, and silica.
We are particularly interested here in two categories in the large family of ceramics: porcelain and ironstone, which are by far the most appreciated for the Arts of the tableware.
Porcelain
Porcelain is a Chinese invention dating back more than 1000 years. It was brought back to the West in the 14th century by Marco Polo and quickly became a luxury coveted by royal families.
It was only at the beginning of the 18th century that the secret of its manufacture was discovered in Europe, thanks to the numerous research carried out in Germany at the request of the King of Saxony, Frederick Augustus. The very first porcelain factory in Europe was Meissen in 1708, followed in 1740 by Sèvres in France, and a few years later by England in Chelsea.
The particularity of porcelain lies in its composition that makes it both very hard and incredibly fine. The secret kept for so long by the Chinese was the kaolin ! The porcelain paste is therefore based on kaolin, quartz and feldspar.
After finishing and drying, the porcelain pieces are first cooked around 900°c (1652°F), then enamelled and cooked again at 1200°c minimum (2192°F). This high temperature cooking allows to fuse the material and to give it its characteristic transparency and impermeability. Many decorating techniques then exist (by hand, transferware, stencil, etc.) but this is another story ....
So we recognize porcelain by its whitness, its finesse and transparency. If you see the light coming through by placing your object in front of a lamp, it is undoubtedly porcelain. Antique porcelain pieces of the eighteenth century are thicker than the one of today, but still let through the light.
The second clue will be a possible signature on the back, which can indicate the place of production, the name of the manufacture or if it is porcelain (sometimes the 3 at a time, sometimes nothing ...).
Here are the places of production of yesterday and today, the best known in Europe (non-exhaustive list):
FRANCE | GERMANY | SWITZERLAND | ENGLAND |
Limoges (nombreuses marques) | Saxe (Meissen) | Langenthal | Staffordshire |
Sèvres | Bavaria | Nyon | Bow |
Mehun-sur-Yèvre | Saar | Genève | Chelsea |
Longchamps | | | |
Paris ... | | | |
Other small hints as a bonus: the contact of the porcelain is cold and smooth, the specialists also recognize it by its sound, different from other ceramics.
Ironstone
Fine hard earthenware, English clay, semi-porcelain, opaque porcelain, all these words actually refer to the same material more commonly known today as ironstone.
In fact, there are several families of ironstone, only a laboratory analysis could distinguish them, but there is no need to go into so many details ....
No, there’s no iron in it! So why this name? Simply a commercial argument, because the rendering is harder and stronger than porcelain, it was compared to the enamelled iron plates called indestructible, which is more than questionable !
The recipe varies according to the region, and its paste, more often ivory coulor than white, can contain kaolin, feldspar, charred bone, flint among others.
His authorship was discussed, but it was in Staffordshire (England) that it was first invented by Josua Spode in 1805, with the aim of developing a more resistant material than porcelain and thinner than traditional faience. Then further improved by Charles James Mason who filed a patent in 1813.
This was the time of the full industrial boom, and the English quickly developed new manufacturing techniques that made it possible to produce mechanically in large quantities, at a lower cost and excellent quality. Thus the ironstone pieces will become more affordable than porcelain and will experience an incredible rise throughout the nineteenth century.
In France, it is mainly in the North and the East that production intensifies at the same time. The most famous factories such as Digoin, Sarreguemines, St Amand, Lunéville,Creil et Montereau, are the biggest employers in their region, with several thousand workers until the beginning of the 20th century.
Their collections are found on all tables, from the most prestigious to the most modest, the difference being in the care given to the decor.
The oldest models are cream-colored, then the manufactures managed to bleach the dough more.
It is therefore a thicker material than porcelain, which does not let light through. Despite its enamel layer, It is also more porous, because it is cooked at lower temperatures than porcelain. This is noticeable in case of chipping, the material is not smooth as porcelain and also seems less cold to the touch. Besides, ironstone can't stand moisture, so I recommend you not to let it soak in the sink and to wipe it quickly to avoid cracking enamel and moisture stains.
But the first clue to recognize the ironstone is often found on the back of the piece, with the name of the manufacture, even the inscription "Ironstone" or "terre de fer" in French.
"It is a real art that expresses itself in everyday objects, and certainly one of the most affordable art to bring into its interior and to collect."
With these few elements in mind, you will quickly be able to differentiate the porcelain from the ironstone tableware, and you will make your opinion on which one you prefer to collect ...
To resume
PORCELAIN | IRONSTONE |
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