This portrait is painted in enamel on metal. The advantage of enamel over traditional miniature painting (watercolour painted on vellum or, from about 1700, on ivory) is that it does not fade when exposed to light. The process of painting with enamels is, however, less free than the miniature technique and is fraught with danger. The first colours to be laid on the metal support have to be those needing the highest temperature when firing. More colour is added and the enamel refired, the process ending with the colours needing the lowest temperature. Such labour meant that it was an expensive option.

Enamel was first practised in England in the 1630s by the Swiss goldsmith Jean Petitot at the court of Charles I. It was reintroduced around 1680 by a Swede, Charles Boit, and achieved wide popularity with the work of Christian Friedrich Zincke of Germany. Both Boit and Zincke were goldsmiths by training. In the early 18th century a number of miniaturists took up enamel in order to offer their clients a choice. But as the market for all portraiture grew in the mid 18th century and as miniature painters worked on ivory with increasing confidence and bravura, enamel painters such as Jeremiah Meyer decided to learn their rivals’ art.

In 1757 Meyer’s father had paid C. F. Zinke the substantial sum of £200 to teach his 14-year-old son Jeremiah the lucrative art of enamel painting, with an additional £200 for materials. By 1769, when he became a founder member of the Royal Academy, Meyer was a highly respected miniature painter, working in both watercolour on ivory and in enamel on metal, as in this example. He was one of those artists whose work on ivory took the traditional watercolour art to the new levels of confidence and bravura that marked the work of the next generation of miniaturists.