There's a female tile craftsman in Shizuoka Prefecture who has trained as an "Onishi," a craftsman specializing in demon tiles, the only one of her kind.She is Reina Nagasawa, daughter of the second-generation owner of Nagasawa Kawara Shoten, a roofing tile business that has been operating in Shimizu Ward since 1971.
From her efforts to revive the Shimizu tiles that were lost in the 1974 heavy rains,to creating original products that treat tiles as a material rather than just a roofing component.
We delve into Nagasawa-san's work of promoting the appeal of tiles and passing them on to future generations in a two-part series. In the first part, we will show you the little-known process of creating demon tiles.
Ms. Reina Nagasawa
Born in Shizuoka Prefecture. A tile craftsman and daughter of the second-generation owner of Nagasawa Kawara Shoten Co., Ltd. She creates tile accessories as "Onirei," the only female "onishi" (demon tile craftsman) in Shizuoka Prefecture who has trained as an onigawarashi.
(*Article content is based on information at the time of the interview)
#1 The meticulousprocess of creating unbreakable Onigawara
To achieve robustness as a roofing material, not a work of art
──What we're looking at today are palm-sized demon faces. What's the process for making them?
It's a process of shaving and cutting off parts formed from a mold, then attaching each part to the base.
If you just stick them together, they'll break, so it takes several steps to bond them securely. The fangs aren't in the mold either, so they're added later. That's why each face is slightly different.
This "kakikiri" (scoring) process is crucial. When applying clay, we don't use adhesive; we join the clay pieces together.
You scratch deeply with a bamboo spatula so that lines cross in a cross shape, then after interlocking both parts, you place the piece on top and press it firmly. If you do it shallowly, it won't stick, so this depth is important.
──Is the process the same for small items and large demon tiles?
It's the same. When joining clay pieces, you absolutely must do this properly. Onigawara (demon tiles) are roofing materials, so the primary consideration is that they must be sturdy roofing materials, rather than works of art. We prioritize making them robust.
Furthermore, we always perform a "chamfering" process, rounding off the corners with a metal spatula. By eliminating sharp corners and making them round, they become less prone to breaking. That's why Onigawara actually have many small facets, and right-angled parts are made so that the edges aren't too sharp.
Even after joining parts, we erase the grooves once more and score the clay again. We repeat the process of preventing cracks many, many times. I think that's a unique characteristic not found in other works of art.
#2 Techniques for making demons "frightening"
A face that looks down from the roof. An expression that is only completed when viewed from below
──Are there any specific techniques for making Onigawara look scary?
First, the parts are layered on top. Onigawara are meant to be viewed from the roof, so it's not about how they look from the front, but how scary their face appears when viewed from below.
That's why the eyebrows and cheeks are sculpted to appear as if they're overhanging from above.
Another point is the position of the nose and ears. In a human face, the nose and ears are typically aligned. However, with Onigawara, the nose and ears are drastically misaligned and slanted.
This creates a powerful, non-human, vigorous, and angry expression.
──There are smiling demons too, right? Are there Onigawara that aren't scary?
Smiling demons are said to bring good fortune, while angry demons ward off evil. Both require an impactful presence, so the nose and ears are generally in this position for demons.
Also, there's this part called the juzu (rosary beads). While it might vary slightly depending on the demon tile, we generally try to make them in a count of 108.
──Is the use of a three-part plaster mold also for creating that "scary face"?
Exactly. With a normal mold, the entire shape has to be trapezoidal for it to release, so it inevitably gets a slope.
That wouldn't make the demon's face scary. So, we intentionally divide it here to allow the mold to be taken at an angle.
That way, even with a mold, we can create parts that overlap, like the eyebrows and eyes.
This work can only be done by a select few within our company. After they're made, I always check them for cracks, ensure they're beautifully crafted, and verify all the polishing of the parts before firing them.
#3 Tile color is created by firing technique
Raw gas, carbon, and the time of sealing. Until the birth of lustrous silver
──We're in front of the kiln, is the tile firing method completely different from pottery?
With pottery, it's common to bisque fire first, then apply glaze and fire again. Tiles are different. They go directly into the kiln in their raw, unglazed state. Single firing is a characteristic.
Furthermore, not just any kiln can fire tiles; it requires a specialized tile kiln. This kiln is the only specialized tile kiln in Shizuoka City.
──What is that orange part?
This is a distinctive feature that even kiln operators are puzzled by. We send flames through burners from below, raising the kiln temperature to 1100 degrees Celsius.
Then we seal the kiln and let it cool. Into that, we directly introduce raw gas from a gas canister.
As the gas fills the kiln, the oxygen inside is depleted, and the carbon in the gas combines with the clay, smoking and carbonizing the clay. That's how it turns lustrous silver.
It's similar to making charcoal. Tiles are unique because their color comes from the firing method, not from glaze.
──What happens if oxygen gets in?
It won't become lustrous silver. It turns silver because of incomplete combustion. Since it's in a smoked state, if oxygen enters, it will burn, and the silver film won't adhere. It will turn brownish.
This is a failed piece. Here, the maximum temperature was too high, burning off the surface silver film and making it blackish.
On this side, the gas application started at too low a temperature, so the surface became full of holes. This smoked silver color is an extremely delicate art.
In the old days of daruma kilns, they fired with firewood, and in the final process, after sealing the kiln opening, they would pack in pine needles. The pine resin would then coat the tiles beautifully, giving them that lustrous silver color.
Since Shimizu has Miho no Matsubara (Miho Pine Grove), I heard that children used to have part-time jobs collecting pine needles, and those were used.
