Narrator: This swampy mush is about to become
some of the world's most expensive paper.
At first, hanji is barely visible.
And once it emerges from this bath, it's delicate.
But after it dries,
Korean paper can last thousands of years.
The most expensive version of a single sheet this size
costs over $22.
So, what makes hanji so long-lasting?
And why is it so expensive?
Kang Gapseok has been making hanji for 45 years.
The fibers he's washing
were once the bark of a paper-mulberry tree.
Narrator: Hanji is a versatile material
that's prized within Korea.
Today, it's used for everything
from calligraphy to clothing.
And because of its strength,
institutions like the Library of Congress and the Louvre
have used hanji to restore centuries-old books.
The secret to its strength are these long, weblike fibers
and the traditional method of sheet forming.
After boiling, bleaching,
and painstakingly cleaning each fiber,
it's time to head inside.
Kang uses this machine to transform the tough fibers
into a mushy pulp.
Narrator: Now it's time to turn pulp into paper.
Fibers flow across the bamboo frame
and settle into transparent layers,
almost invisible to the naked eye.
But Kang sees what we can't.
He knows the exact moment when a sheet is fully formed.
After decades of papermaking,
he's able to produce 350 sheets per day.
Narrator: The amount of fibers on a sheet
and their direction determines the strength of the paper.
Moving the frame in one direction aligns the grain.
But the most expensive paper is made
by agitating the fibers in multiple directions.
This is slower, but it evenly distributes the fibers,
yielding stronger paper.
Each weight of paper requires a different amount of pulp,
and Kang's experience is the key to getting good results.
Narrator: Careful sheet forming is important
because the fiber structure determines
how a paper holds up over time,
especially if it's being folded.
Kang says this process can take four years to learn.
And he has to be careful,
because at this stage, hanji is still delicate.
Narrator: He uses an automated pump to speed up the process,
but it still requires close attention.
Narrator: Despite hanji's versatility,
the ingredients are simple: water, fiber, and glue.
Premium, conservation-grade hanji
uses a natural glue made from hibiscus root,
which disperses the fibers across a sheet.
This type of hanji has a neutral pH,
which is one of the requirements
to be classified as permanent paper,
and it's ideal for restoring old documents.
In fact, one study found that hanji
aged two to three times slower
than paper from medieval Europe.
For less expensive hanji, Kang uses a chemical glue.
While Kang immerses himself in flowing water,
the other side of the workshop is dedicated
to drying the freshly formed sheets.
Yoon Jungae tears the crisp, clean hanji
off a hot plate set to 88 degrees Celsius.
She's been working with hanji for 40 years.
Narrator: She dries paper used for conservation
at a lower temperature, around 40 to 50 degrees.
Narrator: After a lifetime of working with hanji,
this process has become muscle memory.
Her horsehair brush is an extension of her hand,
used to smooth out hanji without scratching it.
This workshop used to be bustling with dozens of employees,
but Kang says he's had to downsize as demand has decreased.
Narrator: Artisans sell the most expensive hanji
to institutions and museums that use it for conservation,
like repairing pages in books or even fixing sculptures.
But Kang says demand for this type of hanji
isn't that high.
It's also more expensive and labor-intensive to make,
since he must beat the fibers by hand
instead of pulverizing them in this machine.
In Korea, hanji has been used for over 1,000 years.
But in the West, conservationists often train
on washi paper from Japan.
And while some Western institutions
have recognized hanji's quality,
widespread use abroad isn't common.
Kang says he's stopped exporting hanji
and only sells domestically.
In recent years, the South Korean government
has started initiatives to increase demand for hanji,
but it will take time
before artisans feel the benefits of these programs.
Narrator: Despite hanji's uncertain future,
artisans like Kang continue to maintain this ancient craft.
And many are working tirelessly
to bring new uses and awareness,
hopeful that the hanji industry
can last as long as the paper itself.