Amakusa Porcelain Stone: The Secret of Arita Porcelain. Clay Loved by Living National Treasures | Koda Toudo

The Whiteness of Arita Porcelain Comes from "Stone." What is the Miraculous Raw Material "Amakusa Porcelain Stone"?

"The glaze color isn't coming out beautifully..."
"I want to make white porcelain, but the quality isn't stable..."

If you have such worries, the cause might not be the glaze, but the "Clay Body".

The translucent whiteness of Arita porcelain cannot be created by glaze alone.
The secret lies in a special stone called "Amakusa Porcelain Stone" (Amakusa Touseki), which is rare even globally.

In this article, we introduce the secret of its quality along with photos from the manufacturing site of "Koda Toudo", a professional manufacturer that Fukaumi Shouten trusts and recommends from the bottom of our hearts.

1. A Rare Stone Usable as a "Single Ingredient"

Usually, porcelain clay is made by blending several types of soil and raw materials to create plasticity and refractoriness. However, Amakusa porcelain stone is different.

No Blending Needed: A Miraculous Balance

Amakusa porcelain stone is a "Single Ingredient" raw material that can be used as porcelain clay just by crushing it and adding water.
This is an extremely rare property globally.

• Plasticity for molding (Quartz)
• Glassy quality that hardens upon firing (Sericite)
• Plasticity for molding (Kaolinite)

These minerals are mixed in a miraculous balance within nature.
Because "nothing unnecessary is mixed in," a pure whiteness without muddiness is born.

2. The Traditional "Stamper" Method: Rare even in Japan

The reason Koda Toudo's clay is superior is not just the material. There is a commitment to the "manufacturing method" that other production areas cannot imitate.

Power of the "Pestle" Creates Plasticity

While many clay factories use efficient rotary crushing machines (Ball Mills), Koda Toudo uses the traditional "Stamper" (Stamp Mill).
This is a method of crushing stones by pounding them with a heavy pestle.

Although it takes a very long time, the impact causes the stone particles to become appropriately angular and interlocked, creating "Strong Plasticity" and "Body (Koshi)" that cannot be produced by mechanical grinding.
The smooth extension when throwing on a wheel comes from this process.

"Elutriation" and "Iron Removal" to Protect Whiteness

The crushed stone is dissolved in water, and only the components suitable for porcelain clay are extracted. Then, iron is removed using powerful magnets.
Finally, by passing it through a fine sieve as shown in the photo, it is reborn as smooth, pure white porcelain clay with no impurities.

3. Why is "Koda Toudo" Clay Chosen?

Because of such careful work, Koda Toudo's clay continues to be chosen by many professionals.

Reason 1: Pride in Delivering "Unchanging Quality"

The scariest thing in porcelain is "making it the same way as last time, but failing because the clay changed."
Koda Toudo's commitment is "To supply unchanging products stably without delay."
Because they thoroughly anticipate and deal with problems, they maintain constant quality at all times.

Reason 2: Clay Loved by a Living National Treasure of White Porcelain

Its high quality is proven by history.
Mr. Manji Inoue, a potter designated as a Living National Treasure (holder of Important Intangible Cultural Property) in the field of white porcelain, also used Koda Toudo's clay "exclusively" for many years.
The ability to make him say, "Without this clay, that work would not have been born," lies here.

Reason 3: Individual Orders & Factory Tours Available!

This is the point Fukaumi Shouten recommends most.
While raw material manufacturers usually deal mainly in "BtoB" (Business to Business), Koda Toudo kindly accepts "Individual shipping via Online Store."
Since you can purchase in units of 10kg, individual artists and hobbyists can easily get "authentic clay."

Furthermore, they actively accept "Factory Tours" as shown in the photos earlier.
If you see the impressive sound of stampers and the process of making clay with your own eyes, your attachment to your work will surely deepen.

Summary: Good Clay for Good Glaze.

It is said that "a bad workman quarrels with his tools," but in porcelain, it is no exaggeration to say that "Clay Selection" determines 80% of the quality of the work.

If you want to bring out 100% of the potential of Fukaumi Shouten's glaze, please try using the authentic Amakusa porcelain clay. You will surely be surprised by its ease of handling and the beauty of the fired result.