Enamel – the witchcraft of watchcraft

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There is something rather mystical about the art of enamel. Maybe it’s due to its ancient origins, or because it’s one of watchmaking’s best-guarded secrets, or perhaps because enamel starts its life in a boiling cauldron, before being ground in a pestle and mortar, and ending up in fires hotter than hell!

There is nothing witch-like about the enamellist Dominique Baron from L’Atelier, however. This charming young woman, with her blonde hair and welcome smile, is happy to share her magic. Self-taught, she perfected her art in the workshops of some of the watch industry’s most famous brands, before becoming independent and then setting up L’Atelier with the support of the Richemont Group. Employing ten people, L’Atelier works for a number of brands (not exclusively Richemont companies) who are in search of some artistic alchemy. Ms. Baron was kind enough to take Europa Star through all the magical and mystical stages of the fabrication of an enamel dial that mixes art, chemistry and a spell or two!


Dominique Baron

In a nutshell
Enamel is a type of glass that is applied onto a metal, porcelain or glass support and heated until the two fuse together. Its properties include a mixture of silicia, a sand-like material, and a variety of other substances such as soda, potassium carbonate and borax that are prepared following ancient recipes.

From the cauldron to the pestle and mortar
But before starting, one of the essential tools in the making of enamel is a clay melting pot that is hand made and then dried for seven months at 30 degrees Centigrade. Once it is ready, the pot is gradually heated in a kiln for eight consecutive days to a temperature of 1,400 degrees Centigrade / 2,552 degrees Fahrenheit. The raw enamel materials are then heated in this melting pot until they form a colourless, crystal-like liquid. Different metallic oxides are then added to the molten matter to obtain one of a large variety of colours. Copper makes greens and turquoise, cobalt creates blue, magnesium produces browns, platinum becomes grey, a mix of copper oxides, cobalt and magnesium make black and borostannates make white. It takes an average of 14 hours in the kiln before the matter has fused and can be scooped out with a ladle and laid on a cast iron table (for transparent enamels) or put in a cast iron mould (for opaque enamels) to cool.
The result is a glass like plate which is then crushed and ground into a rudimentary powder. The enamellist normally purchases the different coloured enamels in powder form, but they are also available in plate form or in crystals the size of bath salts. However, all three types of enamel are a long way from being pure enough to be used on watch dials.


Minature painting of an English gentleman
on èglomisé crystal by Angular Momentum
MAGNOLIA by Delaneau

The spells and potions of preparation
One of the biggest problems today for enamel artists is the poor quality of enamel. It is not that the suppliers are doing a bad job, it is just that 99 per cent of their production is for industrial purposes – street signs, casserole pots, bath tubs – not for the delicate art of dial enamelling. In addition to this, many coloured enamels, such as black and some reds, used to contain lead and arsenic. For safety reasons, these recipes have now been modified, greatly reducing the quality of many of today’s en-amels. “We now have to find other solutions, new technologies” explains Dominique Baron, “Although we are lucky to have a huge collection of over 250 colours in stock.”
The enamellist has to continue the task of preparing the enamel by a process of careful washing and cleaning. The enamels are crushed and ground in an agate pestle and mortar (agate because it is harder than enamel and is one of the only materials that doesn’t transfer particles into the enamel mixture). The mixture is meticulously washed with distilled water and then cleaned with nitric acid and washed again until all the impurities are removed. The nitric acid is important because it not only dissolves any non-assimilated metallic particles in the mixture, but also destroys any organic matter and hardens the enamel. The resulting enamel is then conserved in a small pot covered by three parts of distilled water. It is only now that the application of the enamel on the watch dial can begin.

Types of enamel
But before we begin with the techniques, let’s take a look at the different types of enamel that are available. There are two ways to categorize enamels: by their appearance after heating or by their degree of fusibility.
Opaque enamels completely cover the underlying metal dial and are used for covering a totally white dial, for example. Translucent or transparent enamels are like stained glass and leave the metal visible beneath. Opal enamels come somewhere in between opaque and translucent giving an opal effect. In addition, there are clear enamels and coloured enamels. The clear enamel, called fondant (nothing to do with the chocolate dessert, it just means runny!) can be used as a protective layer over the dial or before the application of other enamels, It can also fix the cells for gold leaf pieces, paillons, or for fixing and varnishing certain pieces – fondant de finition. The coloured enamels allow a vast array of decorative possibilities as they change colour in the kiln when the metallic oxides react with the heat. Enamels can be mixed, but the resulting colours do not necessarily correspond to the regular mixing of colours, for example the colour ruby red is a white powder, so the result of the mixing of enamel colours can vary depending on the reaction of the different metallic oxides in the kiln. It is for this reason that many experiments need to take place before work begins.
The degree of fusibility of enamels is extremely important to know. They can be classified as tender, medium, hard or extra-hard and all react in different ways to the heat. The enamellist will start with the extra hard enamels, as they can withstand several firings, and end with the most tender enamels which are more susceptible to burning.

The importance of the base plate
The metal base plate of the dial is usually in gold, silver or copper and there are a number of different alloys as well, each reacting in a different way to the enamel. Before the enamel can be applied, all oxidation of the metal has to be removed in an acid bath, except of course for the noble metals, like gold, that don’t oxidise.
Certain metals can react dramatically with different coloured enamels. For example, light blue enamel on silver becomes a deep sea blue, but on gold it can become a grey/green and a darker grey/green on copper. These effects can be calculated for certain pieces, however if they are not desired, the enamellist will apply a layer of fondant, a clear enamel, to protect the metal before starting with the coloured enamels.

Contre émaillage / Counter enamelling
The contre émaillage or counter enamelling is another essential stage in the process of en-amelling a dial. It consists of placing a layer of enamel on both sides of the dial to stop it from deforming. It keeps the rigidity and the shape of the dial intact. If a round dial is enamelled on one side it will camber and deform inside the kiln. With enamel on both sides, the metal doesn’t distort, although this is not necessary for thick metal dials or the champlevé technique that we will take a look at later.

Managing the kiln
The kiln is where it all happens and an experienced eye is essential in knowing when to put dials in and take them out. In the past, kilns were often placed in a dark room to enable a better look at the colour inside, which was the only way to guess how hot things really were. Nowadays the kilns are fitted with temperature gauges to help the enamellist, but a trained eye and experience are still critical.
Metals can have diverse reactions to the heat shares Baron. “At over 800 degrees Centigrade, metal reacts to the heat. Gold can melt, so you have to be very careful to stay within the limits.”
One of the advantages of cooking dials, instead of cakes, is that a quick peek, even several peeks, doesn’t damage the dial, like it would a Victoria sponge, in fact it is often advised to take certain transparent enamel dials out of the kiln to check them as this can increase the vivacity of the colours.


The kiln, Enamel powder, Application

Enamelling techniques
Dial enamelling consists of applying the meticulously prepared enamel powder onto the dial’s base plate and fusing the two together by cooking them at 840 degrees Centigrade / 1,544 degrees Fahrenheit. The intense heat is due to the high melting point of the enamels and this is why this type of enamelling is referred to as grand feu. Application takes place with an extremely fine brush or needle and usually takes place with the help of a microscope. There are a number of different techniques giving a variety of artistic results.

Le Champlevé – This is the oldest en-amelling technique. Cavities are milled into a thick metal plate, leaving cells that are generally filled with opaque or translucent enamel. When all the cavities are completely filled up to the top, the piece is placed into the kiln. After cooling, the piece is sanded down (leaving it mat) and fired one more time to re-glaze the enamel.

Le Cloisonné – Fine ribbons of metal are fixed onto the dial creating the lines of a picture. The enamel is then placed into the different areas, or cells, of the drawing and the dial is fired in the kiln.

L’émail de Basse taille – The base plate is decorated with engraving or guilloché and then covered with translucent or opal enamel, so that the pattern can be seen through the enamel. These furrows in the metal also ensure a greater adhesion of the enamel to the metal.


Champlevé, Cloisonné*, Basse taille

L’émail Plique à jour – This technique is similar to the cloisoné method. Metal wires or ribbons are attached to a thin copper plate and translucent enamel is placed in the different cells. After firing is completed the thin copper plate is dissolved in acid leaving an effect much like a stained glass window.

Grisaille / contre jour – The grisaille or contre jour technique only uses two colours – black and white. The technique was developed in Limoges, France in the 16th century. It was initially developed to decorate dishes. The enamellist will start by applying the black and then add layers of white Limoges enamel. After each firing, the white fuses with the black to create shades of grey. The thinner the layer of white, the darker the shade of grey.

Paillons – Paillons are small gold leaf motifs, such as flowers, leaves or stars that are placed between two layers of enamel to decorate a dial.

Miniature painting on enamel – The base plate is covered with a single-coloured enamel, usually white. Once the base is enamelled, the coloured enamels are then mixed with an oil binder and painted onto the surface using a microscope for precision. The enamellist will fire the dial after almost every colour application, starting with the most resilient colours (those that can stand successive firings) and finishing with the most delicate hues. This takes extensive research, calculations and practice to get it right. The piece is then finished with coats of transparent enamel to fix the painting, referred to as the Geneva technique.


Plique à jour, Grisaille or contre jour, Miniature paiting on enamel

The Geneva technique – This technique, developed in the Swiss city of Geneva, is the art of putting transparent enamel on top of an enamel painting to protect it and create a perfectly smooth finish, while also enhancing the depth of the painting. It requires up to three layers of clear enamel and several firings in the kiln. If isn’t done correctly, the intensity of the colours can be lost, the dial can bubble or the painting can be distorted.

Explaining the price
With all the challenges involved in making one single enamel dial, you would think that once the dial is encased, the work is finally over, but one of the hardest jobs with enamel timepieces takes place behind the shop counter. Explaining why an enamel timepiece costs twice, if not three times, the same model with a simple dial is no easy task. However, when the consumer understands that an enamel dial can take anywhere between ten to over a hundred hours to produce (in comparison to two minutes for an industrial dial), that it can burn, bubble or explode during any of the 30 firings in the oven (and frequently does) and that only a very small handful of artisans know how to make enamel dials, only then can he or she really start to appreciate the work that goes into each piece. “Even now, I still hold my breath and cross my fingers each time a piece goes into the kiln,” shares Baron. It is also important to note that enamel is incredibly strong and its colours don’t fade with time. This is why historic pieces are as vivid today as when they were first made.

Keeping the art alive
Today it is hard to believe that the art of dial enamelling came so close to extinction. But in the 1970s its popularity had dwindled considerably and then the infamous quartz crisis hit the Swiss watch industry and dial en-amelling almost died out. Thankfully artists like Dominique Baron and others have managed to revive the craft, with the help of watch brands such as Cartier, Corum, DeLaneau, Patek Philippe, Piaget, Roger Dubuis, Vacheron Constantin and Van Cleef & Arpels who believe in keeping these century-old crafts alive.
They weren’t wrong, as enamel timepieces are now some of the most sought after collector pieces and many new consumers are discovering the beauty of this miniature art for the very first time. However, what is really beautiful about the art of enamel is that the process is as fascinating as the result. So there is a real tale to tell and there is nothing that consumers like more than a good story!

*Photos taken from The Enamels of the World 1700-2000 Exhibition from the Khalili Collections at the State Hermitage Museum, St Petersburg, Russia (open until March 14th, 2010). This inaugural presentation features some 320 enamel treasures from around the world. There is also a book accompanying the exhibition, which is a work of art in itself.

Source: Europa Star February-March 2010 Magazine Issue