I purchased this from the artist themselves at an auction over 10 years ago. It is Karatsu-yaki, but I don't know the kiln name. One of the cups originally had a crack in the clay (photos 9 and 10), and water leaks from it little by little. I didn't use this one, but the other two don't leak. None of the three cups have been sealed, so sealing them might stop the leaking. Size: Approximately 9cm in diameter x 8cm in height