An enamel on porcelain copy of Franz Xaver Winterhalter’s portrait of Victoria, Princess Royal (1840-1901), (RCIN 404580).

According to the Osborne catalogue of 1876, this porcelain plaque was produced by an artist working for the porcelain painting institute of Carl Schmidt in Bamberg, and hung alongside a similar-sized enamel on porcelain copy of Winterhalter’s portrait of Princess Alice, later Grand Duchess of Hesse (1843-1878) (probably RCIN 401422) in the Queen’s Sitting Room.

To produce an enamel on porcelain plaque, powdered glass, metal oxides and oil were first mixed to form a paint which was then applied, colour by colour, onto a prepared, porcelain support. After each application of colour, the plaque was fired in a kiln. The process was technically demanding. Each colour had to be fired at a different temperature and therefore had to be applied in the correct sequence, and the enamel had to be added in thin, even layers to prevent chipping once the plaque had cooled. Some plaques could require up to fifteen separate firings in order to fix all of the colours, while larger plaques were typically more valuable as they were more prone to cracking during the firing process.