The single product method starts with the making of the casting mold. First of all the mold for a pot or iron kettle, without a pattern, is made by the caster's hands.








Next the design is pressed. A consecutive pattern of small circular protrusions called "Arare" (hailstones) is generally used. Before the body mold dries, a sharp brass gimlet is painstakingly pressed to form the pattern. In moving toward the upper part of the body, the hailstones become smaller in size.
Besides "hailstones," there may be representations of flowers and birds, animals or natural scenes. Thin paper on which a rough sketch has been drawn is turned over and pasted on the body mold and carved with a spatula. This is work requiring great experience.
The appearance of the product is determined by the angle, form, depth of the "hailstones" and the space between them.

After the circular mold for the handle is attached and the body condition adjusted, the inner mold is prepared. In casting, the space between this inner mold and the outer mold becomes the thickness of the pot.

Fitting together the outer mold and inner mold (core).

After the casting mold is thoroughly dried, the casting begins. The moment the molten metal is poured into the mold is one when even a veteran metalworker feels like praying fervently for success.

When the cast metal hardens, the body mold is removed and the inner mold crushed with a metal rod.

The casting is heated with charcoal fire at high temperature for two or three hours to form an oxidized integument of magnetic oxide of iron on the surface. This not only settles the iron body but is also processing for rust prevention.

The final step is coloring.
After a lacquer undercoating, the heated iron is placed in Sake (rice wine) and then a special paint called "Ohaguro" fermented for several months is spread over the now slightly heated surface of the pot.
The surface of the pot gradually changes into a quiet darkish color.
This is the craftsman's final affectionate farewell to his product.