The juice is strained and evaporated and then mixed with various substances, such as oil, fine clay, body pigment, and metallic dust, according to the ware for which it is intended.

The manufacturing secrets are carefully guarded.

The application of it is very difficult, the sap of young trees being used for first coats, and of old trees for the finishing coats.

It must be dried in a damp, close atmosphere.

For the best work ten or twelve coats are elaborately rubbed down and polished.