Enamelling is an appealing feature of decorative ceramics, trinkets and snuff boxes, whether it is found glazed upon a white clock face or expertly applied in bright colours. Enamel is a versatile material, often used to create texture as well as forming unique patterns and finishes.
Above: different forms of enamel decoration
With time, this once clear and bright medium may begin to deteriorate, requiring professional care to prevent further issues from arising. This article will explore the many forms enamelling may take, as well as the intricate processes that go into its creation and conservation.
What is enamel?
In its most basic description, enamel is a powdered glass that has been fused onto a metallic or ceramic base. This type of enamel is called vitreous.
Above: a Chinese bowl with cloisonné enamel decoration from the late 15th century / early 16th century
There are various forms of enamel decoration that use this process, these may include:
- Cloisonné – metal ribbons applied to form ‘cells’ of enamel
- Basse-taille – a design that is applied beneath a translucent or opaque enamel
- Champlevé – the surface metal or ceramic has carved pits that the enamel coats
- Shipōyaki – a Japanese form of Cloisonné
- Plique-à-jour – a form of Cloisonné that has no surface behind the enamel, allowing light to pass through, similar to a stained glass window
Above: a plaque with champlevé enamel decoration, 1170–80
- En résille – enamelled metal suspended in glass
- Painted enamel – enamel used as a paint to apply an image on a metal or ceramic surface, as seen on Limoges enamel items and miniatures
- Grisaille – a dark surface with a white or light enamel paint applied to create a monochrome image
- Sgraffito – fired enamel coated with an unfired enamel that is partly removed to form the pattern, sometimes seen on building facades
- Safed chalwan – jewels set in a light enamel base
Above: examples of grisaille enamel decoration
The powder that forms vitreous enamel is created from a melted frit of sand, soda, red lead and potash. If the craftsman is looking for a tinted or opaque enamel, they may infuse this mixture with an oxide. Carl Fabergé often opted for a semi-translucent effect, adding different oxides to each layer of frit betweening firing.
Above: a varied selection of antiques with different forms of enamel
The frit is applied to the surface of an object with a bonding agent, traditionally an oil of spike lavender. The object is then fired in a kiln, allowing the new surface to harden and become transparent. This may be completed several times to achieve the desired finish, building layers to add strength and dimension. Enamel decoration is usually low-fired at 700 to 900 degrees celsius.
Above: two examples of Basse-taille enamel decoration, 16th century
Many porcelain items may also be decorated with painted enamel, found as an overglaze on Chinese porcelain such as the Qing dynasty famille rose, jaune, noire, and verte ceramics, as well as Japanese kakiemon. From the late 18th century to the early 20th century, enamel was the main source of colour for porcelain vases, plates and decorative objects. Enamel paint may have a smooth raised texture if it has been layered.
Above: porcelain decorated with enamels in famille verte, kakiemon and famille rose
Miniatures painted in enamel are completed colour by colour. The oxide mix with the highest firing temperature applied first onto a a silver or gold surface. Enamel miniatures required an expert skill, as the artist needed to determine the firing temperature of each paint layer as it went into the kiln.
Above: three miniatures completed in enamel
Caring for objects with enamel decoration
Enamel can suffer from many of the same issues facing glassware. Although it may appear stronger than glass, enamel surfaces can shatter upon impact. Cloisonné or basse-taille may lose fragments of enamel, leading to structural instability. Once enamel decoration or its surface material has been disturbed, it will continue to deteriorate.
Above: an enamel clock face before and after restoration by our team
Cracked or abraded areas may begin to flake away from the surface. When faced with this situation, all broken pieces should be collected – no matter how small – so that our specialist conservator can restore the damage before it worsens.
Our conservators recommend displaying enamel artworks behind glass in a cabinet or table. This will help to keep them free of airborne contaminants and any build-up of dust, as well as helping to avoid accidental damage.
Above: an enamel cloisonné bowl before and after restoration by our team
A stable environment is key for most artworks and enamelware is no exception. Controlling the atmosphere will help to prevent expansion and contraction of base materials, preventing pressure and movement beneath the enamel surface. Enamels may have faced various environments throughout their history, leading to the appearance of fine craquelure or crazing. If this is present, contact our team for stabilisation treatments.
How can we help?
If you have any questions regarding restoration, our team is always happy to help. Email us via [email protected] or call 0207 112 7576