Subscribe to stay in-the-know
Enter your details to receive communications about our products and services, events, and cultural endeavours.
Is Your Enamel Jewellery Actually Glass?
On the difference between kiln-fired cloisonné and cold enamel — and why it matters more than you think.
There is a specific kind of disappointment that comes from watching colour disappear from something you paid good money for. The enamel piece that looked so vivid in the listing — saturated blues, clean whites, a red that seemed almost lacquered — has, after a few months of careful wear, begun to yellow at the edges. The surface looks cloudy. Something has gone wrong, though it is not immediately clear what.
Most people blame themselves. They assume they did something — used the wrong cleaner, wore it in the wrong conditions. But the more likely explanation is simpler, and worth understanding before the next purchase.
Two Things Called Enamel
The word enamel, as it applies to jewellery, covers two entirely different materials that share almost nothing except their name and their appearance in product photographs.
The first is vitreous enamel — glass. Ground silica is fused to metal at temperatures between 750 and 850 degrees Celsius, melting into the surface and hardening into a permanent, chemically stable layer. This is the material used in traditional cloisonné, champlevé, and guilloche work. It is the enamel of Byzantine icons, Ming dynasty vessels, and Fabergé eggs. It is, in the most literal sense, glass bonded to metal.
The second is cold enamel — resin. An epoxy or polyurethane compound, tinted with pigment, is applied at room temperature and cured without heat. It looks almost identical to vitreous enamel in photographs. It costs a fraction of the price to produce. And it behaves entirely differently over time.
What Cloisonné Actually Is
Cloisonné — from the French word for partition — is a technique in which fine metal wires are bent and soldered onto a base to create small enclosed cells, which are then filled with powdered glass and fired in a kiln. The process is repeated multiple times: fill, fire, cool, grind flat, fire again. A single finished piece may require five to ten firings.
The labour involved is considerable. A skilled craftsperson may spend several days on a single bracelet. The colour palette is determined entirely by the chemistry of the glass, which is why traditional cloisonné has a particular depth and luminosity that photography struggles to capture.
The result is not merely decorative. Kiln-fired glass enamel, properly made, is chemically inert and extraordinarily durable. It does not fade. It does not yellow. It does not react to moisture, perfume, or hand sanitiser. Museum pieces made in the tenth century look largely as they did when they were made.
The Cold Enamel Problem
Cold enamel has its legitimate uses. The problem is not the material itself but the labelling.
Resin is sensitive to UV light — it yellows and hazes with sustained exposure to sunlight. It is sensitive to alcohol — hand sanitiser, perfume, and cleaning products strip the surface and accelerate clouding. It is sensitive to heat — a car dashboard in summer can be enough to cause warping or bubbling at the edges.
None of this is disclosed on most product listings. “Enamel jewellery” describes both, equally, and the photographs look the same. The divergence only becomes apparent over months of wear — by which point the purchase decision has long been made.
How to Tell the Difference
There is no single definitive test, but several observations, taken together, build a reliable picture.
Ask the maker directly. A producer working with genuine kiln-fired enamel will know the kiln temperature used, the number of firings, and the origin of their glass powders. Vagueness about process is informative. Authentic cloisonné work has a production story that is specific and verifiable.
Look at the surface under light. Vitreous enamel has a depth that comes from its glass nature — light enters the surface and reflects from within. The colour appears to sit below the surface rather than on it. Resin tends to look flatter, with a more uniform sheen that sits on top of the piece rather than within it.
Consider the price in relation to the claimed process. A genuine cloisonné piece, made by a skilled artisan with authentic materials and multiple kiln firings, cannot be produced inexpensively. A piece priced at the same level as mass-market fashion jewellery is almost certainly not kiln-fired.
On Caring for Glass
Genuine kiln-fired enamel requires less maintenance anxiety than its reputation suggests. Because it is glass fused to metal, it is fundamentally stable — immune to the chemical reactions that degrade resin over time. The practical rules are simple: avoid sharp impact, keep it away from ultrasonic cleaners, and clean with a soft cloth and water if needed.
It does not need to be kept away from water. It does not need special storage. These are the maintenance requirements of cold enamel, not vitreous glass — and conflating the two has generated a great deal of unnecessary anxiety around a material that is, in many respects, one of the more resilient things you can wear.
The things made to last rarely announce it. They simply continue — through seasons, through contact, through the ordinary accumulation of a life being lived.