The Obvara firing technique originated in Eastern Europe around the 12th century, ans was originally used to seal low fire functional pottery. There is a revival of the technique in the Ukraine and the Baltic countries, and has therefore been gicen the nickname of Baltic Raku.
To achieve the Obvara signature, pieces are heated to around 700-900 C and then dipped briefly in a pre-prepared yeast mixture. It is then cooled down in cold water to stop the developing process and “fix” the signature. The result is that every piece is unique and can never be repeated.