All actual pieces are coilbuilt in different technics from grogged German stoneware clay. They are burnished when leatherhard and covered with thin layers of terra sigillata. That is a very fine shiny slip also used in ancient history in different cultures  which I produce from special clay bodies. After a first biscuit firing again a second time layers of terra sigillata are  put on followed by a second firing.

  Then the pieces are covered with a slip and sometimes glazed. They are fired in a gas kiln with following reduction in sawdust. With influence of water the slip crackles away like an egg-shell, the burnished piece appears again.

I call this technique „ VERLORENE GLASUR“ ( Lost glaze).