Narrator: This is ink.
Toshitsugu Okabe is kneading it
until it's as soft as a rice cake.
It's imperative for him to be as thorough as possible,
because a well-kneaded mixture
becomes high-quality calligraphy ink.
It takes at least four years of aging
before these solid ink sticks can be sold,
and even longer for the most expensive ones.
A 200-gram high-grade ink stick from this producer,
Kobaien, costs over $1,000.
And for some other brands,
prices can reach almost $2,000.
Meanwhile, almost double the amount
of commercial liquid India ink can go for less than $9.
So, why are solid ink sticks so sought after?
And why are they so expensive?
It's January in Japan's Nara Prefecture.
Ink producer Kobaien has been making
Japanese calligraphy ink for 450 years.
This type of ink, also known as sumi,
is traditionally sold in the form
of handmade solid ink sticks.
To use the dry ink stick,
calligraphers rub it on an ink stone to mix it with water.
Sumi ink is typically black,
but it can also be tinted brown or blue.
The ingredients are simple:
soot, animal glue, and perfume.
But the quality of these materials
and the time-intensive techniques
required to collect and process them
have a large impact on the final price.
It starts in this room, lit by 100 oil lamps.
This workshop has four rooms like this,
where artisans produce all the soot
they require to make ink.
Two workers are in charge of this stage,
each overseeing two rooms and 200 oil lamps.
They carefully manage the vegetable oil in the lamps
and gradually collect soot throughout the day.
In Japan, this process is called "catching smoke."
Every day, artisans light all 400 lamps
and cover each with a lid,
the underside of which collects soot as the oil burns.
But they can't just leave the lid
in the same place for hours,
because overheating it will prevent soot from accumulating.
The flame must be off-center,
and the artisans must rotate the lid
every 20 minutes for two hours.
The artisans scrape the soot off the top of the lid.
They replenish the oil, and the process starts all over,
for a total of five times a day for each lamp.
These lamps contain rapeseed oil,
the most common choice when producing high-grade ink sticks.
Ink sticks made of soot from even more expensive oils,
like paulownia, camellia, or sesame,
can easily cost up to four times as much.
But artisans must also consider other details,
like the containers that hold the oil
and the material of the wick.
To ensure the quality of the soot,
they use nonporous earthenware containers.
Craftspeople in this workshop even weave
the wicks themselves to exacting specifications.
Narrator: The fineness of the soot grains
determines the final price.
Then there's the binding agent: animal glue.
Unlike most of its modern liquid-ink counterparts,
which use shellac, sumi ink typically uses cattle glue.
For the most expensive ink sticks,
artisans sometimes mix in other types of glue,
such as donkey, deer, and goat.
Kobaien says this improves
the ink's glossiness and texture.
The company buys glue specially made for sumi ink,
which comes in a dry, board-like form.
Artisans dissolve it by mixing it
with 70-degree-Celsius water,
which takes over an hour and a half.
According to Kobaien, dissolving the glue slowly
at a low temperature is key to producing quality ink.
Narrator: But animal glue can have a bad smell,
so sumi-ink makers add fragrance
like borneol and musk to counteract it.
Narrator: The next step is to knead the soot, glue,
and fragrance into a soft dough.
The dough is kneaded every morning by hand and foot.
Toshitsugu takes care to knead it thoroughly,
so the soot and glue are evenly distributed.
That way, the solid stick can eventually dissolve
into homogenous liquid ink.
Once he's properly kneaded the dough,
Toshitsugu cuts it into balls
and weighs them for consistency.
Then he places the balls into molds
and uses a machine to press them into shape.
Improperly kneaded dough results in ink sticks
that don't produce rich color.
Narrator: Kobaien makes about 6,000 of its smallest,
highest-quality ink sticks a month.
It employs a handful of artisans for this,
and the ones tasked with kneading
require the most experience.
It takes five years to train as a sumi ink craftsperson,
but 10 years before they're allowed
to make high-quality ink.
Kobaien produces almost 40,000
of its smallest sumi ink sticks between October and April,
when the cooler weather of winter
ensures the glue can harden during shaping.
But the work isn't done yet.
Drying the ink sticks too quickly will cause them to crack,
making them unsellable.
So artisans rely on a traditional technique,
using oak ash to slowly absorb moisture from the sticks
over a long period of time.
They start by covering the sticks in moist ashes.
Each day, they swap yesterday's ashes with drier ones.
They repeat this process for up to 40 days,
until the ink sticks are about 70% dry.
After, they hang the sticks with straw
and air-dry them in-house for up to six months.
Properly drying and maturing an ink stick
takes at least four years.
The longer the sticks dry and age,
the better they perform and the more expensive they become.
Kobaien itself has ink sticks
that are hundreds of years old.
Narrator: Finally, artisans polish them
and apply the finishing touches.
Now they're ready to be sold
to calligraphers like Sho Azakami.
Calligraphers like Sho
traditionally prefer ink sticks to liquid ink.
But in order to write with a sumi ink stick,
he must first transform it into a liquid.
This requires an inkstone and water.
Sho adds a small amount of water
and rubs the ink stick on the stone, breaking it apart.
He mixes the two to make the liquid ink,
adding more water or more dry ink
until he gets the consistency he needs.
Narrator: But not all sumi inks provide him
with the same writing experience.
Narrator: 95% of Japan's sumi ink is made here,
in Nara Prefecture.
Sumi ink production in Japan
is said to have begun in the seventh century,
when Chinese ink-making methods were introduced by monks.
By the 14th century, sumi ink use was flourishing in Japan.
Though its primary use is for calligraphy,
it's also often used for ink paintings, known as sumi-e.
And because Kobaien must age its ink sticks
for several years before it can sell them,
consistent production is necessary,
or else its supply won't meet the demand.
But that doesn't mean the company wants
to ramp up its production.
Narrator: Kobaien strives to continue making
calligraphy ink using the same techniques
and of the same quality as its founders.