This vase was fired unglazed in a wood-fired kiln. During the long process of the firing, ash within the kiln would land on the vase and fuse with the surface, giving it a natural glaze. On one side, this glaze is an ash gray, on the other is a natural iron red color achieved in the high temperatures in the kiln, forming irregular patches of color. The neck has a yellowish color. The combined effect of the three, and how they work together, imparts a simple, natural esthetic.

　　Bizen ware refers to the ceramics produced in the kilns surrounding Bizen City in Japan's Okayama prefecture. The lid of the box bears writing in black ink reading, "Old Bizen tokuri flower vase," showing that this vase was originally a wine vessel (tokuri), but was later put to use as a flower vase. It is a classic example of Bizen ware.