Vidoro(Bidoro)
Vidoro(Bidoro) is a pooling of natural ash glaze that melts into a vivid, glass-like green on wood-fired japanese pottery — especially Iga and Shigaraki ware. The word comes from the Portuguese vidro ("glass"). Where thick ash gathers and flows during a long firing, it forms translucent green rivulets and droplets, prized in tea ceramics as one of the most beautiful moments of the kiln.
FAQ about Vidoro
Q1. What is Vidro in Japanese ceramics?
Vidoro(Bidoro) refers to the emerald green, glass-like layer that naturally forms on the surface of certain ceramic pieces. It is not created by applying artificial glass or conventional glazes. Instead, as wood fuel (such as red pine) burns inside the kiln at temperatures exceeding 1200°C, the flying wood ash settles on the vessel and melts into a natural glass glaze. Because it is a product of chance inside the kiln, no two pieces ever share the exact same color or dripping pattern. This natural glass effect is highly prized as a distinctive aesthetic feature in traditional styles like Iga and Shigaraki ware.
Q2. Is there anything I should keep in mind when using ceramics with a Vidro finish?
Even though the Vidoro(Bidoro) layer itself is glass, the body of the vessel is still porous earthenware. Therefore, it should generally be cared for in the same way as standard pottery. Performing medome (sealing) with rice water before its first use helps prevent oils and food odors from soaking into the clay. Depending on how the Vidro formed during firing, microscopic pores or kannyu (fine crazing) may exist beneath or around it. After use, wash the piece gently by hand with mild soap and let it air-dry completely in a well-ventilated space before storing. Avoid using dishwashers or microwaves to protect the vessel. To learn more about how to care Japanese ceramics, please read this too.