What is champlevé?

There are different enamelling techniques. Cloisonné or cell technique involves metal barriers being soldered on to a flat base plate and the cells or spaces being filled with enamel. Champlevé works in the opposite way. First the design is carved into a metal plate. An etching needle is used to for more precision, digging out all areas where the enamel should take. The pits are then filled with enamel in varying colours.

With both techniques the enamel is melted and the fired plate sanded. If copper is used, as is the case with the Verdun altar panels, the surface must also be fire-gilded and polished. Since the Verdun altar panels have been melted at over 1000 degrees Celsius, they are extraordinarily resistant.