ENAMELLING
Interview with enameller Vanessa Lecci
- General Description
- History
- Grand Feu Enamel
- Flinque enamel
- Champlevé enamel
- Cloisonné enamel
- Grisaille (or camaieu) enamel
- Paillonné enamel
- Plique-à-jour (or transparent enamel)
- Miniature painting (enamel)
Enamel, millenary in existence, remains a material that is just as difficult to master. Creating enamel requires essentially the same know-how since ancient times. However, it remains a challenging exercise that combines two variables: the proportion of the components and their thermal treatment.
Its main component is silica. It is melted with a ‘flux’, which allows lowering its melting temperature (to about 800°C). The substance thus obtained is extracted from the oven and, before it cools down, additives are introduced to colour it: most often, copper oxides or other minerals.
The colouring agents used are metallic oxides:
- – Selenium (in the absence of lead) for a yellow colouration;
- – Uranium for a bright orange colour;
- – Iron for blue, brown, black;
- – Chromium for green and pink;
- – Copper for green, red, and blue;
- – Cobalt for a deep blue and green;
- – Manganese for purple;
- – Metallic gold for a deep red (Cassius purple).
This first step produces a block of coloured glass. It must be heated again and then cooled to break it into pieces, which are crushed in an agate mortar with a pestle of the same nature.
Each colour is ground separately. When a powder of equal grains is obtained, the enamel is washed with distilled water about ten times to achieve absolute purity. The enamel is then mixed with this distilled water to form a paste. It is generally applied with a brush or spatula on a metallic base of copper, gold, silver, bronze, or iron and fixed by a series of firings in a kiln at a temperature ranging from 650°C to 950°C.
Enamel is a fusible material made up of various minerals, made very hard by the action of heat, intended to cover different materials for protection or decoration thanks to its unalterable colours.
Enamel refers to the material itself, the technique, and the finished work.
The material is a glassy mass composed notably of silica (similar to crystal). It can be transparent or opaque. It is coloured by metallic oxides. Firing achieves its vitrification.
The technique involves the application of enamel (which is in powder form) on a base (generally gold, silver or more often copper).
The art of enamelling is very ancient. It is not known exactly which people were the first to practise enamelling, but it is known that the Egyptians made jewellery with partitions in which enamel was recognised.
In the 3rd century BC, it was the Celtic lands that held the main enamelling centres in Europe that were decorating pieces of harness or even decorative nails.
At the beginning of the Roman era, enamelling mainly developed in Scotland and England; it was used to decorate weapons, adornment objects, horse bits, and harness plates. Then the Byzantines adopted this technique to decorate pieces of goldsmith’s work for churches from the 6th to the 12th centuries.
From the 10th century, France had an important enamelling centre in Limoges where the technique developed in the numerous goldsmithing workshops of the city. The artists there specialised in making painted enamels, bearing the name of Limoges with subjects in relief.
This golden age was as much technical as it was corporatist: due to the high ecclesiastical demand, the enamel artisans of Limoges nearly invented mass production, while developing techniques such as champlevé.
Miniature-painted subjects, portraits or pictures appeared at the beginning of the 17th century. They were depicted using colours formed from metallic oxides and applied on a watch face or a plate covered with white enamel.
This technique was born in the goldsmithing workshops in the first third of the 17th century. Jean Toutin (1578-1644), born in Châteaudun, was credited with the paternity of this art. His son, Henri Toutin (1614-1683), would also become a grand master of enamel painting.
While this technique of painting on enamel probably originated in Châteaudun, it developed in Paris and Blois. By the end of the 17th century, the industry in Blois and Châteaudun disappeared to establish itself in Geneva. While Paris retained a portion of its activity.
The art of enamel painting was established in Geneva in the same way as watchmaking. Many of these artists were Reformists who, following the Revocation of the Edict of Nantes (1685), sought refuge in Geneva. Others also arrived through the exchange of workers. At that time, when an apprentice became a journeyman, he did what was called his “tour de France”. The same was true for the French who came to Geneva, and some stayed there.
There is little information about the beginnings of enamel painting in Geneva. The best-known artists are those who went to work abroad, notably in Paris or London. For example, one can mention Jean Petitot (1607-1691), Jacques Bordier (1616-1684), and the Huaud family, who brought the Geneva workshops to the same artistic level as those in Blois.
For nearly half a century, the Huaud workshop produced little wonders, of which a good hundred pieces are known to us today while they supplied all of Europe. Their signature is found on watches from London, Paris, Cologne, Amsterdam, The Hague, Haarlem, and Marseille. Most of the painted subjects are drawn from ancient history and Greek mythology.
From 1685 to 1700, they notably worked in Berlin for the Kurfürst of Brandenburg (the future Frederick I, King of Prussia). Contributing decisively to the birth and development of enamel painting in Geneva, the Huaud family can be considered the founders of the Geneva school of miniature, which they also helped to flourish.
In the 18th century, enamel continued to be regarded as a varnish, formed by the vitrification of fusible substances, with silica used as a base to which colouring oxides were added.
It wasn’t until the beginning of the 19th century that the enamel technique was used for the making of our everyday products such as kitchen utensils (pans, bowls, stockpots, casserole dishes, etc.). Thanks to its solidity and resistance to moisture, enamel was also used as a coating on small pieces of furniture for kitchens or bathrooms. With the material’s benefits proven, it was only natural that the first street signage plates made of enamelled sheet metal appeared in 1847. Public services such as the gendarmerie, ministries, or schools also adopted this medium for their signage.
In 1895, the history of enamelled signs took another turn and attracted brands. Enamel was increasingly used for advertising signs: all brands of chocolate, aperitifs, beverages, or cars had their enamelled products.
With growing local demand, the 1920s marked the beginning of mass production and industrialisation. More and more enamelling workshops emerged and contributed to the economy with the creation of new jobs. At the 1925 International Exposition of Decorative Arts in Paris, Limoges enamels were widely displayed in galleries and salons. The success achieved encouraged a new boom in enamel production throughout the century.
After reaching its peak in the 1930s with the creation of numerous industrial enamelling workshops (Jean, Japy, Emaillerie Alsacienne…), the period of the ‘glorious thirties’ and the increase in living standards significantly impacted the manufacturing of enamelled signs. During this period when production and the economy were the main concerns, new manufacturing techniques appeared. In the 1950s, plastic became the star material in the industrial sector due to its ease of use and low cost.
With the emergence of new advertising media such as television, radio, or the press in the 1960s, enamelled signs lost their appeal. Communication now had to be fast, massive, and varied. The introduction of taxation on outdoor advertising in the same year underscored the decline of enamelled signage.
Today, enamelled plates are generally regarded as collectors’ items.
The art of grand feu enamel is a quintessential craft, particularly used in watchmaking. It is the most difficult and delicate technique to master. In return, decorations made with grand feu enamel are exceptionally long-lasting, if not immutable.
Enamel is a base of silica to which fluxes such as sodium, potassium, or lead oxide are added. The colour is then obtained through other metallic oxides or salts such as copper, manganese, silver, or tin.
The mixture is then vitrified, that is, turned into glass by melting. This operation takes place in a kiln heated between 800 and 1200°C. Hence the term “grand feu”, often used in watchmaking. The result is more or less opaque, depending on the mix composition and vitrification parameters. Several cycles of firing and polishing are required to achieve a smooth and even surface.
The piece is thus entirely covered with enamel, leaving no metal visible on the surface.
A translucent or opalescent layer of enamel is applied to a metal plate that has been engine-turned or engraved in low relief.
Engine-turning creates decorations composed of straight lines or curves that intersect or interlace.
Champlevé is a technique that involves carving cavities into a metal plate. This is done with a chisel or acid, formerly referred to as “raising a field”.
The enamel paste (powder mixed with water) is placed into the hollows to fill them. The cavities are often filled with several layers. The finished piece reveals parts of the metal.
This technique is now one of the most known in watchmaking. Contrary to popular belief, champlevé is not exclusive to enamel or watchmaking! It is a generic technique that involves carving out a material serving as a support and then pouring enamel (or any other material) into the created recesses. One could just as well pour in gold, silver, or set precious stones.
Once the surfaces are filled, the plate is fired. Subsequent polishings remove the excess enamel, giving the piece a glossy finish.
This method involves placing wires (of copper, silver, or gold) onto a metal plate to form patterns. The cavities thus created are filled with enamel. During firing, the colours do not mix.
An alternative version exists: in “open” cloisonné, or “plique-à-jour”, the cavities are initially sealed with a thin sheet of copper or silver glue, which is then dissolved with acids. This leaves no background and allows for transparent effects.
This technique involves treating enamel in monochrome in the style of enamel painting. Grisaille is particularly suited to figurative or ornamental subjects. It involves overlaying numerous layers of white enamel on a black background. By firing between each layer, the various layers blend into one another, creating minute variations between the background colour and white.
The grisaille technique with Limoges white was invented in the 16th century, notably to make copies of engravings, which were very fashionable at the time. Some say that Limoges white originated in Limoges. Others assert it was manufactured/invented around the same time in Northern Italy. The mystery remains, but Limoges gave its name to this particular white enamel.
It consists of a mixture roughly equivalent to white enamel except that it contains more oxide than glass and is reduced to a very fine powder. It is mixed with oil to obtain a paste that has roughly the same texture as oil paint. Therefore, it is easier to create gradients and shades of grey than with an opal enamel also used for grisaille (modern technique).
The technique of paillonné enamel involves inserting a tiny metal decoration – a “paillon” – between two layers of enamel, thus creating effects of brilliance through transparency. The paillon is as thin as a sheet of paper.
According to the French Academy dictionary, the term “paillon” originates from the word “paille” (straw). These minuscule objects can take on very diverse forms: geometric (circles, squares, rectangles, triangles), numeric, arabesque, botanical, etc.
In watchmaking, this technique is used to add brilliance and play of light to the dial.
The plate is pierced with a motif onto which enamel will be applied, all on a base of mica (a mineral constituting a translucent background preventing the enamel from escaping underneath). After firing, this base is removed, and the result gives an effect similar to that of church-stained glass windows.
The craftsman’s work involves creating or transferring a design or illustration to a smaller scale to fit the shape of an object.
Both sides of the plate are first covered with white or colourless enamel, and the piece is fired. This way, the back is protected from deterioration, and the front is ready to receive the decoration. Layers of colour (pure oxides) are then applied using lavender oil with a very fine brush, and the plate is fired after each addition of colour.
The miniature painter begins by painting the background, then the decorations, and finally the details, layer by layer, colour by colour, with patience and meticulousness.
Miniature painting offers a richness of colours, contrasts, and details that are impossible to achieve with the different current industrial processes.
This is indeed one of the enamel techniques that should not be confused with acrylic miniature painting.