A blue-green stain produced by the addition of feldspar to a pool of pine ash. It is found in Iga, Shigaraki, and Mifukui ware, and is highly prized. The word “bidoro” refers to the glassy quality of the glaze, and is said to derive from the local name “bidoria,” which is said to be the same as “piri” or “ruri. In the olden days, blue-green was the most noted glassy color, and it is likely that the blue-green color produced by falling ash in the kiln came to be known as beadlo glaze.
