One of the most incredible features of yakishime (refering to the the natural and unglazed pottery of Shigaraki, Iga, Bizen, Echizen, Tamba and Tokoname as well as others) is when the surface appears caught in a moment of time. The ash or flame makes for a keshiki landscape of frozen motion. The drip of ash suspended in time or the hi-iro (fire color) showing the shadows of other pots and pads, these make these potteries visually alive.
When I think of hi-iro, my mind often wanders to the pot illustrated, a large tsubo by a member of one of the large Tamba families, Ichino Etsuo (市野 悦夫). It is thrown from a fine grained clay and the form is precise and noble and the hi-iro decoration shows the pathway of the flames as they licked this pot during the firing. It resembles the wispy pathways of a planetary storm of some alien world. The hi-iro is caused by volatizing fumes within the flame and they lay on accidental, incidental decoration of where the velocity of the fire caresses the pot. Though somewhat serendipitous, the potter must know his clay and kiln and how to fire the kiln for the pot to come out so lively. The beauty of yakishime pottery is the evidence of the flame that says something different to every pot and every viewer, a symphony in flame, burned onto the pot.
(Ichino Etsuo Tamba tsubo used with permission from a private collection)