The exterior of this Tula Bowl was naturally Salt Glazed in our Noborigama, the bowl has a blue glaze.
Salt Glazing incorporates a unique method of glaze creation. Instead of applying a coating of glaze minerals onto the surface of the pot before firing. When Salt Glazing most pots are fired in a special salt kiln without glaze. Salt added to the kiln at high temperature releases sodium vapors that react with minerals in the clay body causing it to melt.
The process is referred to as “vapor glazing.”
The technique dates to 15th century Germany. The discovery of the process likely resulted from using salt-soaked driftwood or brine-encrusted staves of wooden barrels as fuel in wood-fired kilns.