High-Fire Transparent Glaze

A transparent porcelain glaze is more than a protective coating. At firing temperature it becomes a glassy surface that interacts optically and chemically with the body and with pigments beneath it.

In blue-and-white porcelain, cobalt decoration is painted before glazing. The transparent glaze then seals the painting beneath the surface during the high firing. The resulting blue therefore has visual depth rather than sitting on top of the vessel.

Variations in glaze thickness, chemistry and firing can subtly alter clarity, colour and the way underglaze brushwork is perceived.