What is indigo dyeing?

What Is Indigo Dyeing?

 

Indigo dyeing (aizome) is a form of natural dyeing that has been practiced since ancient times in Japan and around the world.

Often referred to as “Japan Blue” due to the beauty of its deep blue color, it has gained attention in recent years and is loved by many people.

 

However, for those who have never actually tried indigo dyeing,

• How is it different from regular dyeing?

• Why does it turn blue?

• How is it dyed?

 

I imagine many people have questions like these.

 

In this article, we will explain the basic principles of indigo dyeing in a way that is easy for beginners to understand.

 

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Indigo dyeing is a dyeing method that uses “indigo pigment”

 

Indigo dyeing is a dyeing method that uses a pigment (indigo) derived from the indigo plant.

There are many plants around the world that serve as raw materials for indigo dye, and the specific varieties used vary by region.

 

Some of the most common include:

• Ryukyu indigo (Ryukyu-ai)

• Japanese indigo (mainland indigo)

• Indian indigo

• Ward’s indigo (European indigo)

 

and others.

 

At the Ryukyu Indigo Labo, we use **Ryukyu indigo (Strobilanthes cusia)**, cultivated in Okinawa, as our raw material.

 

The color of indigo dye is not simply “blue”;

we believe it is a color born from plants—a color that embodies the blue of the sky, the blue of the sea, and a variety of other hues.

 

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In fact, indigo “does not dye on its own.”

 

The fascinating thing about indigo dyeing is that

the indigo pigment does not dye fabric on its own.

 

Indigo, the main component of indigo, is insoluble in water.

Therefore, unlike ordinary dyes, simply immersing fabric in the dye solution will not dye it.

 

Therefore, in indigo dyeing,

we use processes called reduction and oxidation to transform the indigo into a form that can be dyed.

 

Through this reduction process, indigo

 

transforms into leucoindigo (soluble form)

 

—a form that is soluble in water.

 

Once in this state, the dye can penetrate the fibers of the fabric.

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Why Fabric Turns “Green” When Dyed

 

As you’ll discover when you try indigo dyeing,

the moment you remove the fabric from the indigo dye bath, it appears green rather than blue.

 

This is because the pigment within the fabric is still in a “reduced state.”

 

When the fabric is exposed to air, oxygen causes

 

oxidation

 

to occur.

 

As a result, the leucoindigo reverts to indigo,

and is fixed in the fabric as a blue pigment.

 

In other words, the color in indigo dyeing is fixed through the following process:

1. Dyeing by reduction (green state)

2. Oxidation by air, turning it blue

 

This is how the color sets.

 

Witnessing this transformation is one of the great charms of indigo dyeing.

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Indigo dyeing deepens in color through “layered dyeing”

 

With indigo dyeing, it is not possible to achieve a deep color in a single dyeing.

 

In most cases,

 

dye → oxidize in the air → dye again

 

this process is repeated many times.

 

By layering the dye, the color gradually deepens,

• Light blue

• Indigo blue

• Deep indigo

 

As layers of pigment build up, the color gradually deepens, resulting in rich, deep shades.

 

This process creates the unique, deep blue characteristic of indigo dyeing.

 

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Indigo dyeing is a rare dyeing technique worldwide

 

Indigo dyeing is a highly specialized method among dyeing techniques.

 

With ordinary dyes,

 

the dye adheres to the fabric in a water-soluble state.

 

However,

 

indigo dyeing

 

is a rare dyeing technique that utilizes

 

chemical reactions (reduction and oxidation).

 

For this reason, it has been studied worldwide since ancient times,

and even today, it is considered one of the most sophisticated dyeing methods among natural dyes.

 

Traditionally, indigo dyeing has relied on a process called “indigo preparation” (aida-te), which utilizes the activity of microorganisms to ferment the indigo so it can be used for dyeing.

This is known as “indigo preparation” (aida-te).

 

There is also a method called “chemical preparation” (kagaku-date) that uses chemicals developed simply to facilitate dyeing, but I will provide a detailed explanation of that in a separate article next time, so please look forward to it.

 

 

 

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The Charm of Ryukyu Indigo

 

The Ryukyu indigo handled by the Ryukyu Indigo Research Institute

is indigo that has been nurtured within Okinawa’s climate and culture.

 

In Okinawa, since ancient times,

 

it has been used for dyeing banana fiber cloth and clothing

 

and has been a familiar part of daily life. Back when Okinawa was known as Ryukyu, the region relied on trade with foreign countries for its livelihood.

 

Okinawa’s textile culture developed through the blending of weaving and dyeing techniques and cultures from various regions.

Ryukyu indigo is an inseparable part of that textile culture.

 

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Indigo dyeing is even more fascinating when you try it yourself

 

While the process of indigo dyeing can be explained in words,

there are many surprising things you’ll discover when you actually try it.

 

For example:

• The fabric is green the moment it’s removed from the dye bath

• It turns blue when it comes into contact with air

• The color changes depending on the number of dyeing cycles

 

These changes are truly fascinating to witness firsthand.

 

At the Ryukyu Indigo Research Institute,

we offer indigo dyeing workshops that everyone can enjoy—from beginners to children to seniors.

 

We invite you to experience the world of dyeing with Okinawan indigo for yourself.

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Tap the image to go to the indigo dyeing workshop reservation page.

Please take a look.