Quenaon works with around 20-25 basic colors, which are confected into the desired hue through a precise recipe of fine enamel powder, metallic oxides, and pine oil. But don’t expect to reach for your rules of primary colors here – this is enamel, and its own animal. Pink, for example, is one of the most difficult enamel shades to reproduce, and is nothing like simply mixing red and white. “In enameling, that actually makes it gray,” explains Quenaon, who has to first prepare the dial with a sheer enamel base, which adds additional complexity. “When you fire it, pink can completely disappear beneath the transparent enamel,” she says. “There was actually pink in all three paintings, so that was a challenge.”
Firings at intense 800°C heat not only change the color compositions, but can also cause them to run. “The colors can mix up so you have to work in different zones,” Quenaon says. “It’s complex and time-consuming.” All in all, some 15 to 20 firings are needed to achieve the desired hues – which is on top of the 15 or so firings at low temperatures of 200°C to dry the paint. Every single firing risks dial breakage, too, which means scrapping the whole thing and starting again. Each dial takes about two to three weeks to finish, with the Klimt as tricky as the Courbet. “They’re all complex in their own way,” Quenaone says.