Have you noticed the colour of the Tokyo Olympics and Paralympics logo? Indigo might not be the first colour you associate with the land of the rising sun, but it in fact holds an international reputation as “Japan Blue”. While this “Japan Blue” has regained attention in recent years, it actually has a long history of production in Japan.
Japan Blue
How long a history? It is thought that indigo first came to Japan from China, by way of the Korean Peninsula, as early as the 8th century! The armour of samurai were popularly dyed in an auspicious shade of indigo known as kachiiro (勝色 winning colour), a legacy that continues today in the indigo jerseys of Japan’s national soccer team. With the cotton boom in the Edo Period (1603-1868), the use of indigo dye came to be widely spread amongst the general population as well.
And while this “Japan Blue” has been cultivated across different parts of the country, Tokushima Prefecture (徳島県) was and remains a major producer. Indigo is known as ai (藍) in Japanese, and it’s not hard to guess its local importance when there’s even a town called Aizumi (藍住) in Tokushima, literally meaning “indigo life”!
What’s more, indigo dye from Tokushima is of such premium quality that it has been branded across Japan as Awa ai (阿波藍), Awa being the old name for Tokushima. At its peak in the 1800s, Tokushima indigo was in wide demand throughout Japan. The importance of awa ai in upholding “Japan Blue” was recognised in 2019, when it was certified as Japan Heritage.
Its beautiful hue is not the only reason why indigo is so well-loved. The indigo plant has actually always been valued as a medicinal herb, even before it was used for dyes. Its many health benefits have been recorded in medicinal notes preserved through the generations, including its effectiveness against mouth ulcers, poisons, nausea, and fever.
With all our modern health fads, it’s no surprise that these medical uses have extended to diet as well. In recent years, indigo has garnered interest as a health food rich in fibre, minerals and most strikingly, anti-oxidising polyphenols. It even beats blueberries in this aspect, containing four times the antioxidant of the fellow blue power berry.
Even as a dye, indigo is more than just a pretty colour. It also confers anti-inflammatory and anti-bacterial properties to materials! In Japan, indigo clothing have been touted to relieve poor circulation and dry skin (perfect for the current winter) since the Edo Period, and today these properties have gained renewed interest as indigo has become the “in” dye for not just shirts, but also socks, handkerchiefs, and even curtains and wooden wall panelling in homes.
So how exactly is this magical blue created? Let’s take a look at the process carried out at its major production site of Tokushima.
From green leaves to indigo dye
The cultivation of indigo begins in March each year, when the seeds of the indigo plant are sowed beneath a thin layer of soil. They then take about a month to sprout, upon which thinning is carried out. In another month, five to six leaves are produced, and this time transplantation is performed: four to five stalks are bunched together and replanted at 40cm intervals. From this stage, meticulous weeding is required, as the sprouts rapidly mature. Around June, when they hit about 50–60cm, that’s when you know it’s harvest time! In fact, double harvesting: after the first batch of leaves are reaped, a second batch regenerates.
Once harvested, the leaves are immediately carried to the dye artisan’s house and subjected to a cutting machine. Then, they are blown with a fan—not to dry them, but to separate the leaves from the stalks, which fly different distances due to their weights. Simple, but ingenious! The actual drying of the separated leaves takes place naturally under the sun, after which the leaves are stored.
Come September, the stored leaves are fermented through the addition of nothing but sprinkles of water every five to seven days. And just like that, a dye of the richest colour is produced, with simple materials yet remarkable human effort and ingenuity!
Indulging in indigo
After hearing so much about this intriguing indigo, you’d surely be keen to experience it in some form the next time you visit Tokushima. Luckily as mentioned, indigo has been experiencing another boom, so there are many ways you can do so!
If you feel like indulging in a fancier souvenir, you could get not only some indigo clothing, but indigo leather products! Indigo’s vivid and rich character, as well as the unique gradients it tends to produce, make it an expressive colour well-suited to leather, a material that likewise gains character over time.
Foodies can also have a taste of indigo through juices and herb teas infused with powdered indigo leaves, or healthy indigo-incorporated dishes. There are even indigo supplements!
As aforementioned, indigo has become popular in interior decor as well, and given its historical value, you may also find many traditional crafts tinted in “Japan Blue”.
There’s definitely much more depth to this wondrous blue than words can express, but hopefully this introduction has gotten you intrigued with indigo, and perhaps curious to visit Tokushima, the very site where it is produced!
Header image credit: AI/TOKUSHIMA
This article is written in collaboration with Tokushima Industrial Promotion Organization.
