True Blue: The Process Behind Making Japanese Denim

An American phenomenon spurred the most significant fashion movements of Japan. Japanese Americana — from which you get Japanese denim. It is the quintessence of Japanese streetwear.

Aditya Roy
7 min readJun 4, 2022

Have you heard the song Japanese Denim by Daniel Caesar?

He talks about how a pair of jeans will last him a lifetime, and hopefully, so does his love life. I just hope he finds the right fit for him.


That’s the story with every denim enthusiast. We are spoilt for choice now. What strikes me is how inundated the denim market is with multiple variants of jeans. What were once miners’ clothes are now worn by children.

So, why did I bring up a Daniel Caesar song? To crack that joke? Well, until now I had only heard about a hand-counted number of denim brands — Levi’s (obviously), Lee, Wrangler, American Eagle etc. — not really hand-counted.

They are all American! So, in this article, I will be dealing with Japanese denim which is artisanal in nature.

Let’s begin with what makes jeans-well-artisanal.

What is Selvedge?

No, it is not “salvage”. It is selvedge, and you’re not the first to make that approximation. When denim fabric is woven on a shuttle loom, it is sealed and self-finished. Or in other words, self-edged.

Selvedge is also known in Japanese as akamini or “red ear.”

Ever seen people fold the hem of their jeans? Also, have you noticed a cherry red seam peak out near the ankle? Like this…


Now while selvedge doesn’t refer to raw denim — denim that isn’t pre-washed — it only refers to the colored seam on the cuff. But it isn’t necessarily colored, the color is only ornamental. This seam is called the selvedge ID.

Earlier, it helped mills tie back a particular denim fabric to a certain company. Now with modern methods of inventory management, the color is an aestheticism.

Now, what is raw denim? Well, I’ll take the primary case of Momotaro. We’ll mention other brands along the way to elucidate the process.

Raw Denim: Momotaro Jeans

According to Japanese folklore, Momotaro is the name of a baby boy born out of a peach. The boy went on to fight ogres, and he is still one of the popular heroes of Japan.

Momotaro Jeans is one of the most revered brands based out of Kojima, and they have denim that begins from $200. Quite a bit for a pair of jeans, right? Well, the process, materials, and craftsmanship command that price.

Kojima is considered the birthplace of Japanese denim. It has the famed “Jeans Street.” Kojima is a prefecture in Okayama from where many denim brands have sprouted. There are 38 specialist denim shops on Jeans Street.

Kintin Jeans or the Gold Label Jeans cost $2000 and have a wait-list period of almost one year.

Let’s look at the process:


The artisans bundle the denim threads and dye the yarn in indigo. Sometimes it can be synthetic or at times natural indigo. The rate for synthetic indigo is $4–5. The price increases 10-fold for natural indigo.

Natural indigo is extracted from the Indigofera plant. Once, an artisan wrings the same yarn 5–7 times, they spread it and hang it to dry. It does easily wash off his hands, but it can take weeks for clean fingernails.


The Gold Label Jeans command such a high price for many reasons. One of them of course is the use of costly natural indigo. Also, here’s a quick pro-tip…

Don’t take out raw denim in the rain, the colors will bleed onto your shoes.

Momotaro Jeans use Zimbabwe Cotton which is rather easy to dye because it is really white. Although, natural indigo sounds exclusive. Synthetic indigo also shows high contrast fades. It instead depends on the dyeing technique.

These are high-contrast fades on a pair of Iron Heart’s are the result of rope-dyeing…


Although, I didn’t find any natural indigo fades but this is a prime example of great fading in raw denim. Raw denim takes a longer time to fade. But you can speed it up to achieve such fades if you wear them religiously.

Now, most Japanese denim isn’t hand-dyed like the process described above. This is only 0.1% of the jeans from Japan. Also, Momotaro is one of the rare denim houses that handle the dyeing process as well. Most give it to mills.


Toyota once used to make shuttle looms, and since then has phased them out. Most of the looms used are still vintage. Some are even 60–80 years old. But many of them are inoperative. Recent Toyoda looms from the 80s are used.

It takes a lot of maintenance to keep them running. Often, spare parts are next to impossible to find, in case, the machine breaks down. Also, Japanese denim fabric requires 5 times more time than that required on regular denim.

Another thing is that shuttle looms are less precise than projectile looms, leading to rougher fabric. The reason behind this is called loom chatter. The rattling of the machines gives the denim an uneven texture.

So, when we talk of loom chatter, it occurs when the denim is woven at low tension. There are two kinds of roughness and unevenness in texture: slub and nep.

The low tension causes the loom to rattle, and it produces an uneven texture. This is called slub or an irregularity in yarn thickness. Slub is caused by the yarn being woven at different speeds, leading to thicker and lighter sections.

Slubby denim leads to some amazing vertical fades. The Japanese have a term for it as well — Tate-Ochi or “vertical falls” — to refer to the rushing of a waterfall. Take a look at these jeans by Naked and Famous…


Loom chatter also leads to something called nep. It is often confused with slub because it is also a result of loom chatter. Due to the phenomenon, the fabric is dotted with threads that protrude or extend from it.

It looks like this…


Below is an antique loom, the kind of loom that the Kintin Jeans are woven on. The process is snail-paced, and it takes an hour to weave just 10 cm. So, it is another reason why they are priced as much as a second-hand car.


The intensive manual labor that goes into using antique looms coexists with the caliber of the operator. While it is laborious, the end result is that artisanal jeans are truly cemented in craftsmanship and quality.


A great feature of Japanese jeans is that it is significantly heavier than regular denim. Regular denim comes at around 11 to 14 ounces. You might find Japanese denim comes in at over 20 ounces.

It is one of the reasons why Japanese denim feels like a carpet, whereas, regular denim is stiff and starchy. Here is what you get because of heavier jeans:

  • Increased longevity.
  • Substantial creasing.
  • Higher production costs.
  • Great fade potential.

Japanese denim houses pay great attention to devilish detailing. Look at this back pocket by Tanuki…


The red and white represents the flag of Japan. Pretty amazing right? Tanuki is one of the top brands to check out as well. They have perfected the Aizome technique. Something which we will talk about in later articles.

Here is the back pocket of a pair of Pure Blue Japan’s. Notice something?


The back pocket has a leaf. It symbolizes the Indigofera plant. Quite a neat detail, right?

If you come to the attention-to-detail aspect of Japanese denim, this article will become a gallery of examples. So, here’s the last one…


As you can see it is a pair of Momotaro’s. The button features the famed peach iconography, and it ties back to folk tales of the peach boy. The list of detailing in Momotaro Jeans is a testimony to their skill and deliberateness.


When we talk of Japanese Americana, we forget that the American brand Levi’s brought something unique to the world of fashion. But the Japanese give a lot of credit to blue jeans even today.

A fashion item we often take for granted, blue jeans signify rebellion, cultural transference, and coolness for the Japanese. They have melded the fundamentals of Western menswear with Eastern traditionalism.

From ancient looms customized for denim to hand-crafted rivets, the Japanese denim is not just an interpretation of American style. Instead, it is a much-needed refinement in the age of mass production.



Aditya Roy

I’m a copywriter with a passion for learning and playing chess. I write on fashion, technology, and literature. Do enjoy my work and leave any suggestions.