only skill and talent but a lot of experience.
The caseback is based on the grand feu Geneva enamel technique. The grand feu enamels used in the Geneva technique reach their point of fusion at an extremely high temperature, between 800°C and 900°C!
The Geneva technique of miniature enamelling with a protective flux coating is undoubtedly that which requires the greatest expertise from the master enameller. The caseback is first coated with a white base enamel - that is extremely hard because of its high fusion point then undergoes a first firing at a temperature of around 900°C in order to be able to withstand the many subsequent firings in the furnace.
On this white enamel base serving as a “background canvas”, the artist starts by tracing the outlines of the various motifs with a brush consisting of two or three marten’s hairs. This involved a few touches of colour on the chosen shade, placed in successive points in an extremely precise order, moving throughout the entire process from the softer shades to the purer, brighter ones. The extremely fine powders and pigments used for miniature enamel paintings are blended with oils such as lily flower oil, to make them easier to apply.
When the miniature enamelled painting has been completed and fired for the last time, it is generally coated with two or three layers of a finishing flux consisting of a transparent enamel serving to protect the work from the potential effects of ageing. Following the final firing of this flux (at 800°C), a fine polish with an abrasive stone is performed, followed by the final polishing operation after the last vitrification in order to achieve the full radiance and pictorial splendour of the work.
Here are some photos of how this works (even though not specifically on the caseback of the Dear Hunt)