Incense Box: Seto Ware, 1200s-1300s. Old Seto, also called Koseto ware, was typically coated with an ash glaze in the mineral feldspar, which produced a yellow or grayish-green glaze. This palette appealed to medieval Buddhist priests and samurai alike. The practice of burning incense in religious, court, and domestic settings dates from the early 700s in Japan.