What Makes Japanese Denim So Special?

Selvedge denim is produced worldwide, but in the denim enthusiast community, Japanese denim is often praised above the rest. Many denimheads consider Japanese fabrics to be the best of all – but what, exactly, makes Japanese denim stand out in the minds of so many when compared to American, Italian, or Turkish denim? Is it all just hype, or are there real differences that give Japanese denim a unique edge?

The answer is, honestly, not necessarily. Not all selvedge denim is created equal, so while most selvedge denim is high quality, that selvedge line doesn’t automatically mean that it will age in a distinct manner or wear well over time. Denim produced on a Japanese selvedge loom can have radical variations in color, weight, and texture from one fabric to the next. By understanding how different characteristics affect denim’s aging, longevity, and appearance, you’ll be better equipped to find the right kind of denim for you and judge the quality of any particular denim.


First of all, Japanese denim is often made on old shuttle looms – not American Draper looms imported to Japan (as is sometimes thought in popular myth), but vintage Toyoda looms. When the Toyoda Model G was introduced in the 1920s it was a major advance for fabric weaving machinery, creating such loyalty that looms descended from the 1924 models are still used today by Japanese mills. Vintage Toyoda looms make fabric in very limited quantities – the typical roll of denim will be a little under three feet wide and the weaving processes is much slower than on modern machines.

1924 Toyoda shuttle loom

Modern looms, in comparison, are very fast and efficient plus make a precise and consistent fabric. The thing is, experienced denim fans don’t want precision – it’s actually the variation and imperfections of the weaving process that lend character to the best Japanese denim.

When comparing a nice sample of Japanese denim to a typical off-the-shelf pair of jeans, you’ll immediately notice the difference in texture – most jeans have a smooth surface, but Japanese denim is often surprisingly hairy or rough. This can often be quite intimidating at first for someone used to wearing soft, pre-faded jeans. Pure Blue Japan is renowned for its slubby fabric, faded Samurai denim has a complex, grainy texture, and The Flat Head is known for its heavy vertical fading. These qualities are accomplished by modifying the looms to chatter as they weave, creating a unique texture. Such brands often keep their exact weaving methods a carefully-guarded secret, such as Oni.

In contrast, selvedge looms set up to weave an even, neat roll of denim can produce a fabric that (aside from the selvedge line) is virtually the same as non-selvedge projectile denim. It’s worth learning as much as you can about the denim on a pair of jeans before you buy in order to determine what the fabric has to offer beyond a selvedge line. Just because a fabric is selvedge or even made in Japan doesn’t mean that it’s better than any other denim.


Rope Dyeing

The dyeing process is traditionally a crucial ingredient in giving the best Japanese fabrics their flavor. Japan has a rich history of textile dyeing, dating back to kimonos from hundreds of years ago, a technique preserved today in techniques like kasuri dyeing. Likewise, Japanese denim is created with a variety of different proprietary dyeing processes.

One of the most striking properties of Japanese denim is the variation in color from one brand to another. While many recent Western brands use the same (admittedly high-quality) Cone White Oak selvedge denim on their jeans, this means that one pair will fade very similarly to the next.

On the other hand, the faded color of Japanese denims can be dramatically different from one brand to the next. Some brands, like Fullcount, Denime, or Warehouse excel in reproducing vintage American-style denim with a lighter overall color. Brands like Tenryo, The Strike Gold, and Pure Blue Japan produced dyed weft fabrics to give their denim unique fading properties, such as a gray or brown overcast. The Flat Head and Eternal use an extra-dark dyeing process to create denim that fades to a rich turquoise blue over time.


Another element of Japanese denim is the weight. While Japan produces plenty of lightweight fabrics, most denims of 20 oz. or more comes from Japan. Comparatively, most other types of denim weigh between 11 and 14 oz.

While weight is largely a matter of personal preference, the added durability of a heavyweight denim makes it appealing to many denim enthusiasts. Besides the additional toughness and warmth in cold weather, heavyweight denim tends to give thicker creases, and thus often faster or more defined fading than lighter materials.  However, just because denim is heavyweight, doesn’t mean that it will be longer-lasting than regular denim. Heavier denim puts more stress on the stitching, which can lead to faster thread breakage in some cases, especially on jeans with all-cotton stitching.


Another important factor in giving denim its character is the post-weaving processing involved – or a lack thereof.

Sanforization is the most familiar process, by which unwashed denim is “shrunk.” While unsanforized denim will experience considerable shrinkage from washing, sanforized denim usually doesn’t shrink much. Sanforized denim generally lasts longer than unsanforized; the main tradeoff being that it fades in a much softer manner, and high contrast doesn’t come as readily to sanforized denim. Sanforized fabrics are softer and smoother than unsanforized when new.

Singeing is the process by which the loose, hair-like fibers on the surface of the denim is burnt away, contributing to a smoother feel. Like sanforization, this process is extremely common on mass-produced denim. Most large companies are concerned with producing a fabric that’s immediately soft and comfortable. However, many high-quality raw varieties of denim are singed as well, such as some of R.J.B.’s fabrics.

Calendering – Calendering is a process where denim is evened out by passing through heavyweight rollers. Heat and pressure create a smoother, more comfortable fabric. Calendering contributes to the uniform appearance of most denim, like the other processes.

Mercerization – This process involves soaking the fabric in a chemical solution, which causes the fiber to swell. Mercerization also gives the denim a smooth sheen. It’s one of the final processes the denim undergoes.

Although many Japanese mills make fabrics with all of these processes, the high-end artisanal brands like Strike Gold and Studio D’Artisan, among others already mentioned, forgo these processes completely. This is called loomstate denim, and a few Japanese mills are among the only places in the world where true loomstate denim is still commonly produced.

The manner of processing can have dramatic ramifications for the feel, durability, and aging potential of a pair of jeans. For example, a pair that’s been sanforized, singed, and calendered, such as 3Sixteen’s SL-100x or Iron Heart’s 634S, will be comfortable when new and won’t need to be soaked before wearing. The wearer can enjoy a raw pair of jeans that will have a unique shine before the first wash, and if well-maintained the denim will last for a long time due to the even composition.

The smooth, even texture of sanforized denim.

The smooth, more even texture of sanforized denim.

By contrast, a pair of loomstate jeans, such as Samurai’s S710xx or Flat Head’s 3005 will have a much rougher, hairy, and uneven feel and appearance. These jeans can be harder to deal with, between trying to correctly determine your size and effectively shrinking to the proper size, and the less uniform nature of the denim can make it less durable than sanforized fabrics. However, the payoff is a sharper, more defined quality to the creases and points of stress, as well as a more textured appearance to the denim.

Unsanforized denim - note the uneven, sharper texture.

Unsanforized denim, uneven, sharper texture.

It’s worth pointing out that just because denim is Japanese, there is absolutely no guarantee that it will have these characteristics. Many Japanese fabrics are sanforized, treated, and have a less complex texture. Just because a brand boasts that their fabric is made in Japan, there is no certainty that it will have any of these qualities. The best Japanese denim is distinguished by the indigo dyeing processes, the weight and weave of the denim, and the texture of the final product. All of these factors contribute to a pair of jeans that is designed to show optimal evolution over time.

It’s this combination of qualities that give Japanese denim a unique character rarely seen on other fabrics. While other denim mills are quite capable of producing denim with similar qualities – particularly when it comes to forgoing post-weave processing – most are more concerned with speed, efficiency, and consistency.  By re-discovering the virtues of a rough and unrefined fabric, other denim mills might one day produce their own fabrics rivaling the qualities of Japanese denim.

Particularly due to the rising interest in jeans made entirely in America, Cone Mills has experienced a resurgence of activity; however, their denim is mostly sanforized and undergoes other processing.  Last year, however, the mill introduced their first loomstate fabric in over sixty years, made exclusively for Roy. Perhaps someday soon, some enterprising individuals would be willing to start their own denim mill on American soil, dedicated to special batches of artisian denim on the same level of uniqueness as Japanese fabrics.


Kyle lived in Japan for several years and has worked in the denim industry. He likes writing, playing electric guitar, and listening to Japanese indie rock bands.

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    Congrats Kyle on this well written, researched article. Something that you forgot to mention is the Cotton Concept – Most Japanese brands buy up a lot of Zimbabwean cotton, ( and other long stable cottons vs upland cotton) This in combination with the Toyoda Looms ( set at low speeds), and Dying Process makes its so Special. But there are other denim mills catching up – Theres some real amazing cotton concepts coming from Pakistan, and China both with amazing textures – all Ring Spun, Long Stable cotton. All on Vintage Selvage Looms – of course nothing touching Japanese Denim – but they are close. Congrats again.

    • Kyle

      Japanese denim is my favorite, but I think that other countries developing similarly high-quality fabrics is definitely a good thing.

    • Johnson Benjamin

      I suppose you can not be on top For ever.

    • trehsu

      Too bad I won’t buy denim made from Zimbabwean cotton.

      • Devan Prithipaul

        Why not?

        • trehsu

          Mugabe’s policy on land distribution is heinous and unjust. A severe lack of funding due to vertical integration and lack of investment in farmers by ginning companies. Many small plot farmers are getting screwed out of money and lack loans while white owned land is being illegally seized. A general lack of cooperation along with the interference of a hugely corrupt government prevent Zimbabwe from influencing prince in the international market. Small plot farmers produce 99% of cotton and without loans and funding from ginning companies small prot farmers are suffering. Zimbabwe’s economy has declined by nearly 50% since the 1980s. In general, South Eastern Africa lacks horizontal integration and government involvement in the cotton industry, even though it’s often one of the top cash crops and one of the largest contributors to their GDP. Western Africa, like Mali, Burkina Faso, Benin and Chad have better horizontal integration with private and state owned ginning companies aiding in funding and teaching beneficial farming techniques.

    • Nicholas Kearney

      Correction to your vocab, sorry but its long staple, not stable. Staple = Fiber. Pima and Egyptian have .75-1 inch long staples, most other cotton is around .5 inch long. So it’s fiber length that is important in high quality and durable fabrics. The ring spun is how the yarn is made, and typically only long staple fibers can be ring spun into yarns.

  • Jeroen

    Great read Kyle. Have to agree with Mohsin here, the rest of the world is coming. Would be interesting to see how the denim community will respond to these new countries and their development.

  • Devan Prithipaul

    One of the best articles in a long time. Good job Kyle.

    • BillygoatsGruff312


  • Richalicious

    I agree with everyone on here so far…. great article :)

  • Grazfather x

    Great article. I have a pair of 3sixteen+ which are unsigned and uncalendared and I wouldn’t have them any other way.

  • Johnson Benjamin

    Well. I just learned a lot. Thanks for the good read. My father works in a plastic mill/plant. It is surprising how a lot of these finished processes are similar.

  • http://www.mbschool.com.ua/ Val Pyatak

    awesome article! Thanks to Kyle and Rawrdenim :-)

  • Chris

    I enjoyed the article but I had one question Kyle ‘While many recent Western brands use the same (admittedly high-quality) Cone White Oak selvedge denim on their jeans’ – I don’t understand what this means… selvedge is what I see as a process rather than a type of denim, so what is Cone White Oak? Where is it sourced from? Is it a colour? Please enlighten! Thanks.

    • Kyle

      It’s just the name of a type of denim that the Cone mill in North Carolina makes. There’s nothing wrong with this fabric, but it seems all the startup made-in-USA brands are using it. The texture and color is rather plain in comparison with the better Japanese fabrics.

  • ReasonB

    This is great, thanks for the insights, I am an artist and hardcore jean enthusiast, denim is the only fabric in the world that survives my lifestyle. We had denim textile mills here (southeastern USA) until the 80s/90s. I came across your article while researching some of my vintage denim, thanks again for this wonderful educational resource, I will bookmark for sure!

  • denimjerk

    roy denim, over priced denim.. ugly leather patch..seriusly.. roy denim ist like jumping into bandwagon.. it take years to catch japanese jeans processes.. and when we do reach at their state.. they will reach another level.

    anyway kyle, its a good articles but u left out alot of details on cotton..3 generations of family run business…etc..etc..

    • Nathan

      You really do own up to your username! Roy is a great jean & a great American denim story that will continue to grow I’m sure! You don’t like the leather patch??? Get a life! Yeah they are expensive jeans but, is that a reason to rip into the company? ROY is trying to bring that high end selvedge denim back to the US along with a handful of other US denim companies! I’m sure you have spent plenty on a pair of jeans like most of us that frequent RAWR DENIM or do you just troll the comment’s?

      Kyle great article as always!