Indigo blue, exclusive to REN.

Indigo blue, exclusive to REN.

Indigo blue, exclusive to REN.

BABY BUFFALO" brings out the charm of the material that buffalo around 6 months old possess. The soft and fluffy texture of the finished leather without hiding natural flaws and uneven coloring is appealing. The more you use it, the more you can enjoy its "luster.




Among them, "Indigo Blue" is a special color that REN has been particular about.

The deep, clear blue color is tinged with purple depending on the light, and the more it is used, the more its blue color changes.

REN first encountered this color in 2017. He says that leather dyed with indigo dye was very rare. The soft and supple texture of buffalo, and its fluffy natural grain are characteristic, and above all, its charm lies in its changing expression.


▲Wallet in baby buffalo (indigo blue), used by staff


The more you use it, the more glossy it becomes.

The fact that many of REN's staff members use baby buffalo also speaks to its appeal. The daily expression of indigo blue changing to a deeper blue.

The sheen and shade of color vary from person to person, depending on the user. The process of changing to one's own unique color is one of the joys that only those who have used the product can enjoy.





Getting in touch with the leather's background

The "leather" we come into contact with every day is the leather that has become a product. Although we touch our favorite baby buffalo wallets every day, we rarely have a chance to touch the background of the leather.

What kind of process does the leather go through before it takes shape and arrives at REN?

We covered the process of producing REN's exclusive indigo blue.



Ito Sangyo, which makes Indigo Blue, is located in Soka City, Saitama Prefecture.

It is a tannery with a history of about 69 years. With the exception of a few processes, we ask them to do everything from dyeing to finishing of baby buffalo. The leather processing process can be divided into more than 20 steps. The number of processes, which varies depending on the material and finishing method, shows the amount of time and effort involved.


Soka City, where Ito Sangyo's factory is located, is known as "Leather Town" and has a thriving leather industry.
Soka City has rivers and underground water sources to secure water, which is essential for the leather processing process, and is close to Asakusa, where leather is traded. In the past, the leather industry flourished in Soka City because of its location.



The number of leather companies is shrinking due to various factors, such as wastewater problems associated with processing and the increase in inexpensive imports from overseas. Although the number of companies is shrinking due to a variety of factors, the leather industry is still developing, with craftsmen's solid handiwork and technical skills, and always keeping an eye on new developments.



From white to indigo blue

REN's baby buffalo begins with dyeing the leather in a state called "crust" after the tanning process. Imported from Pakistan, the leather in the crust state is carefully selected.

The surface is white and the texture has a flat look.

From this pure white state, the fabric undergoes dyeing, drying, and various other processes to achieve the special indigo blue color.


First, the dyeing process is performed by a wooden machine called a "drum".

In a circular machine nearly two meters in diameter, leather and indigo dye are placed and rotated for dyeing. The sight of several large drums lined up in the factory, each moving without stopping, was impressive.



Dyeing with wooden "drums" is a method that has remained unchanged since the company's founding.

Baby buffalo is a cowhide that is around 6 months old, so its surface area is relatively small compared to that of adult cattle. This drum can dye approximately 50 pieces of leather at a time.



The craftsman's experience and sense are the key to the timing of the dye application.

Dye is fed into the drum based on the condition of the leather, the climate, and its timing. Everything from temperature control to drum rotation time is left to manual labor.



After a full day of dyeing, the leather is left to rest overnight in a drum, and the next day, it is pulled out by the craftsman's hands.
After dyeing, the fabric is left to rest overnight, a process unique to indigo dyes. Compared to other dyes, it takes about twice as long.


Indigo blue is a more time-consuming color than others.




Wind and Oxidation

On the second floor of the factory, leather that had been dyed was neatly arranged.
Ito Sangyo's factory, built in the same style as an elementary school building, has high ceilings and large windows that allow natural breezes to pass through.

This wind is an important material for indigo blue.

Exposure to air causes the indigo dye to oxidize, stick, and change color



Equally spaced, swaying in the wind, blue-dyed leather.

The craftsmen carefully stretched and spread the leather by hand, piece by piece, and laid them out. The leather is dried thoroughly in this place, one to two days. It is not always finished as desired because of the rainy days, the lack of sunny weather in winter, and the use of natural winds. Leather processing is also a work that is side by side with nature.

Heat is sometimes used to dry leather, but this hardens the leather and spoils its texture. The best way to maintain the original soft texture of leather is to dry it slowly in the natural wind.



Leather is a very time-consuming thing.

"The wet leather is spread out one by one by hand and dried. Each piece of leather is completely different in shape and thickness, so this kind of work can only be done by hand. Leather is a very time-consuming process."

"It is a very time-consuming process," Mr. Ito murmured as he gazed at the indigo-blue leather that waved in the wind, a remark that left a deep impression on me.


There are a number of operations in the leather processing process that cannot be left to machines. The sense of the craftsman's hands and delicate care for the leather are indispensable for the finished product. At Ito Sangyo, there are currently 11 craftsmen who maintain these skills.





Unwavering commitment to color

Ito Sangyo's strength is its commitment to "color".

As is the case with the indigo blue that REN commissioned, the company's strength lies in its technical ability to faithfully reproduce colors in response to color samples that serve as a guide for the finishing process.



After drying, the surface of the leather has an uneven white color. This unevenness is the difference in the color tone from the color sample and the areas that have not been fully dyed. This difference is adjusted by spraying indigo dye again.。

A large conveyor belt is used for dyeing in the finishing stage.



A sprayer attached to the top sprays a thin layer of dye onto the spread leather surface. While rotating, the sprayer sprays a thin layer of indigo dye onto the surface. As it moves on the conveyor belt, the uneven white color changes to a uniform blue after drying.


"If you add too many layers of color, you lose the natural look of the leather. Indigo dyes are more likely to have a natural leather-like texture if they remain a little uneven."


Mr. Ito says so.
Layers of dye can be used to eliminate unevenness in color. However, to what extent can the original expression of leather be utilized?

Not only the reproducibility of the color sample, but also the original charm of the leather must not be erased.

Ito Sangyo places emphasis on this. Therefore, indigo dye is sprayed twice at most. On this day, REN's indigo blue was finished after only one spraying.


I thought it was a perspective that could only be held by someone who fully understood the appeal of the leather.



Natural beauty

"Uniform surface" and "evenness" are not the only criteria for beauty.

I felt the belief that REN's leather is not only beautiful but also has a natural beauty. I feel this way when I look at the finished leather.



It takes a lot of time and processes before a piece of leather becomes a product. Even though I was aware of this fact, I still found many things to notice when I saw the handiwork of craftsmen working for the first time.

The technique of "handmade" cannot be fully conveyed in a single word.


A special color only for REN becomes a special color only for the user.

We hope you enjoyed such indigo blue.



See the list of BABY BUFFALO products



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