Petrus Spronk

The bowls he makes are not glazed, but burnished.

I learned the art of burnishing from the Pueblo Indians of New Mexico. The Pueblo culture did not have the glazing technique and developed burnishing (polishing the clay by rubbing it with a very smooth stone before the bowl is fired) to make the clay non-porous, to some extent.

After burnishing the bowl, it is fired in a wood fired kiln to a temperature of about 900 degrees C. In terms of ceramics this is a relatively low temperature. Were the bowl to be fired to a higher temperature the burnish would be lost. After the firing the bowl is smoked in order to create the black colour.

The combination of burnish and smoking under intense pressure creates a harder and more durable surface; however, in terms of a glazed bowl it is soft and needs care with handling.

One consequence of the low fired unglazed bowl is that it cannot be used to contain liquid.

He does not create the bowls as containers, but rather as objects of contemplation.