Raku

Well as the potter, Carla Pownall, had used Western methods for Raku, I had to investigate, and the explanation is down below.  As someone who has used oxygen reduction in dyeing with indigo, one of the most exciting things is that when you draw the wool from the dyepot, it's ability to turn dark blue as you draw it very slowly from the pot into the air.

     

"After making the pots for Raku, they are bisque fired to 1000 deg.C. I then put various glazes onto them, all of which I have made. These glazes are designed to crackle. The pots are then re-fired outside in the garden in a kiln using a gas burner. When the kiln reaches the required temperature to mature the glazes, usually at approximately 1000 deg.C. I remove them, red hot and glowing, and drop them into bins containing sawdust. The sawdust immediately ignites and a lid is placed over the bin to exclude the entry of air. The pots, still burning and needing oxygen to do so, use all the oxygen they can take from the atmosphere in the bin and from the glazes themselves. For example, a glaze made with copper oxide (normally green) will burn away some of the oxygen which is present in it, thus becoming copper coloured. Areas of the pot left unglazed become black due to the dense smoke generated in the bin. This smoke is drawn into the body of the pot and into the crackles of the glaze."

In  Japanese methods the pottery was used for the tea-making ceremony historically,

Well Pat LS says, " just use the water that you get from washing rice (before it’s cooked) to seal the clay (it’s just rice starch after all). It takes a few months at least for the protective layer to build up. I can’t see any reason though why other natural sealants can’t be used. Such as fat, thinking of prehistoric pots here which of course thousands of years later still hold traces of their contents.  On the whole I think I shall not use water in the vases though.....

This photo taken from Carla Pownall site, the little pots remind me of those pots you would find in a Victorian dump.

But Bil and Ryes website has some other photos..