Raku is a Japanese technique for ceramics. The glazed object is burnt in an open fire (instead of heated in the kiln) in a closed container or in a hole in the ground, and left there to cool. Because at some point there is no more oxygen in the closed space, it is extracted from the enamelled surface. Certain chemical reactions occur (I don’t know which). With ceramics he result is a craquelé effect and very beautiful special glaze.
This process can be applied to vitreous enamel as well, with spectacular glaze and colours. In this bowl, raku is combined with small areas painted with silver nitrate. When burned, the silver nitrate lines turn into actual silver.
I use raku with white enamel, coloured enamels and with an opalescent black. In addition, certain enamels change as a result of the raku process, resulting in beautiful shimmering copper-red, or other colours.
All the bowls are examples of raku fired copper bowls.