An essential material for the creation of kutani ware. A look at how and where clay is made.
There would be no kutani ware without clay
When mentioning kutani ware, people’s minds typically fixate on imagery of elaborate paintings and enamel designs, but clay is the absolute minimum requirement for kutani ware production. It is what enables artists to actual make their creations. So, how exactly is clay made?
To answer this question, I headed to Taniguchi Seidosho in Komatsu-shi. Taniguchi Seidosho is a 3rd generation clay-shop. Taniguchi Seidosho develops several types of clay to meet customer needs, and delivesr clay not only to local kilns and writers, but also to the whole country.
Furthermore, Taniguchi Seidosho is developing their own original brand “HANASAKA”, which strives to bring out the most attractive aspects of clay as a material.
After a short walk, the first thing I was shown by Taniguchi third-generation leader —Taniguchi was the art of cerabo kutani.
Cerabo Kutani is an abbreviation for Kutani cerabo, and is a composite creation from multiple types of kutani ware. Taniguchi also provides opportunities to experience kutani ware exhibit and sales, as well as pottery firing, molding, and painting.
You can watch the entire process of creating clay from-scratch at Taniguchi Seidosho!
At Cerabo Kutani, there is a soil mill managed by Taniguchi Soil Factory. The machines here are not just for display. They are used in the daily operations of clay-creation. The clay created here is used to create pottery and is given to artists so that they can craft their creations. By observing the machinery used to produce clay, one can see the full picture of how clay is created for. These types clay shops that are located in Ishikawa prefecture have been dwindling in their numbers, and only 2 clay shops remain to this day.
(Taniguchi is one of these shops. ) Clay shops have truly become a scarce commodity.
One of our methods of clay production is a method that utilizes the stamper, and has continued through the generations.
One of these involves using the stamper, which is used to crush the ceramic stones that form the base of clay, and then utilizing a manufacturing called water elutriation to create the clay. According to Taniguchi-san, all of the ingredients that will be used in producing clay will be filtered out from any unwanted substances.
This is done by using the stamper, which crushes the materials and strips the components needed for clay out of the mass as a whole.
Once this process of separating minerals is completed, the material then undergoes water elutriation. This process will serve to further remove any impurities.
While these machines are utilized to speed up the process, this process has remained unchanged throughout the history of clay production. I was then given a more in-depth explanation to the precise process.
A time-consuming process through the stamper – The process of creating clay through water elutriation
- Pulverize porcelain stones to a powder. Utilize the crusher to remove any stone impurities from the materials.
- Remove all moisture
The water absorbency properties of Hanasaka porcelain stone is particularly high. Even in powder form it will absorb a high amount of water, so it will dry quickly. To achieve the perfect balance with the stamper, be sure to operate at the perfect humidity.
- Run the purified stone mix through the stamper.
Using a mallet or similar machinery, pulverize the stone to a fine powder.
Porcelain stone pieces with continue to shrink in size, while silica and feldspar chunks will remain intact.
- Water elutriation
Soak the pulverized stone powder in water. Feldspar and silica chunks are comparatively dense, so you should be able to differentiate the clay materials from feldspar and silica chunks through a difference in buoyancy. Scoop out the feldspar and silica chunks. The picture below shows the removed feldspar and silica chunks after this process ↓
Repeat steps 1 to 4 until you have collected enough clay materials.
All of the steps up to this point are to be completed in the Ceramic Kutani laboratory. From here on out all steps are to performed at the factory adjoining Taniguchi Seidosho offices.
- Filter out iron and other impurities
When a set amount of muddy clay has been accumulated, remove impurities with a vibrating shaker or an electric magnet. If impure iron particles remain in the compound, it will create burn marks that will remain on the pottery during the firing process. Thus, it is important to be thorough during this process.
- Remove moisture (evaporation)
Insert the purified clay into an evaporating machine, which will press the clay as if wringing it to remove any moisture from the compound. The removed moisture will be collected and flow downward.
The particles of Hanasaka porcelain behave like a sponge and are particularly absorbent. The particles will be filled with absorbed water due to the previous process of water elutriation.
The clay may be shipped after all moisture has been removed, and shipped after all of the air is removed from the clay, and it has been kneaded in a clay kneader. (Below: clay that has run through the kneading machine)
Even using specialized machinery, the porcelain stone that will be turned into clay still needs 7 hours in the stamper. The process of water elutriation also takes a considerable amount of time.
In addition, the process of putting claying materials through the stamper, and then the process of water elutriation must be repeated multiple times.
It will then take 10 hours to remove all moisture from the clay compound.
Through observing this process, I realized just how much time goes into producing clay.
Furthermore, there are many factors to consider including how humidity may impact the process of pulverization, and how the process of water elutriation often involves work not only performed by machinery, but is a process that is meticulously guided by hand in many instances by clay producers. Seeing this personally gave me a look into the level of passion workers have for this craft.
Well then, let’s look at one more means of production.
The allure of productivity; A look into the process of producing clay through a trommel; a method that became the backbone of clay production at it’s peak.
- Insert ingredients into the trommel.
Insert all ingredients that will eventually be turned into water and clay into the trommel, which will function as a large-scale mixer.
- Squeeze all ingredients with the trommel.
An equivalent amount of pebbled to raw materials are inserted into the trommel, which serves to rub up against the ingredients, mixing them thoroughly.
- Remove all impurities and moisture from the mixture.
After this, remove all iron particles by utilizing an electromagnet. Subsequently, remove any remaining moisture from the muddy clay to complete the production process.
A trommel is thought of as a piece of equipment, but it is a really a very large-scale machine. With each cycle a trommel can produce around 2.5 tons of clay. Using stampers can be a long and tedious process. Considering the demands for higher productivity, Taniguchi-san’s father and previous Taniguchi president introduced the use of the trommel.
By adjusting the exact makeup of the clay composition in each pass, it is possibly to produce different types of clay to fulfill the exact needs of each project.
What are the specific characteristics of both production methods?
The process of using a stamper with water elutriation is especially suited for times when we need to use a pottery wheel. Especially when create a larger piece of pottery, the clay that we can create through this process is ideal.
Taniguchi-san also spoke about the intrinsic value of using this method. ” Despite the fact that we have introduced a mechanized stamper, this is the original method of clay production. In other words, There is the added value of historical accuracy we can achieve with this method. Regarding this point, I believe that clay produced through the use of a stamper will only increase in value in the future.
The use of a trommel is a manufacturing method that makes it possible to mix materials to make clay. By changing the exact mixing ratio of each compound, it is possible to make clay that suits a more specific purpose, such as clay that is suitable for molding with good mold release and clay that has a small shrinkage rate suitable for tatara molding. (rewrite)
Hanasaka porcelain as an original clay ingredient
Hansaka porcelain is a big part of the history of セラボ九谷. This type of porcelain was discovered during the second half of the Edo period. This was such a key discovery, that if hanasaka porcelain was never discovered, the craft of creating kutani ware would likely not have continued to modern day. . Since the discovery of hanasaka porcelain, it has been used as a vital component of kutani ware, and has supported the entire industry.
When I asked Taniguchi-san about how workers determine the quality of porcelain stone that is collected from mining areas, he had this to say: “The biggest different would have to be the degree to which ‘weathering’ has progressed. Stone that has been weathered is of higher quality. This is because it is soft, and can easy be crushed by hand. On the other hand, stone that hasn’t be weathered is much harder. When I heard the word ‘weathering’, I could see the amount of time required to produce porcelain stone at an astronomical scale, all through the forces of nature to create this previous recourse. I understood that scale required to create the porcelain stones, that have been the backbone of around 360 years of prided history in creating kutaniwares.
The painting of kutani ware is a sight to behold.
At the base of this however, is a process of crafting clay from the most humble of recourses. When thinking about these processes of cultivating clay and porcelain stone, it truly makes you appreciate kutani ware all the more.
Please take a look at “HANASAKA”, the original brand of Taniguchi production who was kind enough to supply me with the information relating to the clay-production processes in this article.
The information provided on this page regarding Kutani ware and Cerabo’s various facilities is really fun to look through as well.