How Kutani-yaki is Produced｜The Process of Making Kutani-yaki

Kutani Ware: A Proud Tradition of Ishikawa, Japan

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Renowned both historically and artistically, Kutani porcelain is one of Japan’s finest ceramics, admired the world over.
Let’s take a look at the journey each piece travels before it reaches completion.

1. Quarrying the Raw Stone

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Kutani ware begins with Hanasaka tōseki, a porcelain stone quarried in Komatsu, Ishikawa Prefecture.
Discovered in the late Edo period (mid‑1800s), this stone has supported Kutani production ever since.

2. Turning Stone into Clay

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The stone is crushed, refined through several stages, and formed into clay.Because Hanasaka stone is rich in iron, the fired body acquires a subtle gray‑tinged white, prized for its depth. The clay is also unusually plastic, making it easy to throw on the wheel.

Thanks to modern clay makers, special blends suited to slip‑casting are now available as well.

3. Forming the Shape

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Artisans shape the clay into vessels or figurines using various techniques:

Wheel‑throwing – A lump of clay is spun and drawn up into sake cups, bowls, vases, and more.

Slip‑casting – Liquid clay is poured into plaster molds, ideal for both tableware and ornaments and suited to efficient mass production.

Hand‑pressed molding (traditional figurines) – Individual parts are pressed into molds by hand and assembled—a time‑consuming craft now largely replaced by casting.

Coil building (hand‑building) – Long clay ropes are stacked and joined to build the form.

Slab forming – Uniform sheets of clay are cut and combined, perfect for angular shapes or panels.

4. Biscuit Firing

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The shaped pieces are first bisque‑fired.

While climbing kilns fueled by wood were once standard, today gas and electric kilns dominate.

↓At Miyayoshi Seito—one of Kutani’s historic kilns

the bisque firing reaches about 800 °C (1,470 °F) for 6–7 hours, leaving the clay a warm reddish‑brown.

5. Glazing

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In the glazing stage (se‑yū), the bisque ware is quickly dipped so the glaze coats evenly.

When fired, this liquid becomes a glassy layer that seals and beautifies the surface—an operation that demands the practised speed of skilled potters.

6. Glost Firing

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Glost firing (honyō) also now uses gas or electric kilns.

Packed tightly in the kiln at Miyayoshi Seito, the glazed pieces are fired at about 1,300 °C (2,370 °F) for 12–15 hours.

The body turns a pure white, while the glaze clears and develops a rich gloss.

7. Overglaze Painting

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Designs are sketched first in gosu, a cobalt‑, manganese‑, and iron‑based pigment that fires to a deep black.

Traditional Kutani then layers the “Kutani Gosai”—five signature colors of green, yellow, purple, dark blue, and red—over the gosu lines.

The remaining four colors are applied only over the black outlines; painting over the red would cause it to disappear in the kiln.

8. Enamel Firing & Completion

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A final firing at 800–900 °C (1,470–1,650 °F) fixes the enamels.

The muted pigments brighten, transforming into luminous glassy layers.

Because those enamels are translucent, the black gosu beneath gently shows through, revealing the delicate patterns that are a hallmark of Kutani’s brilliance.

From clay preparation to forming, firing, glazing, and meticulous hand‑painting, each stage is entrusted to master craftspeople.

Precise temperature control—honed by generations of experience—along with carefully formulated glazes, pigments, and brushes, all play indispensable roles. When every step flows seamlessly, the result is the remarkable ceramic art we know as Kutani yaki.