About Kendo Indigo Dyeing

This is the eighth in a series of interviews with Mr. Tsuyuki Mikiya, president of Musashibo "Kensen," a specialized cleaning service for kendo armor.

Last time, we were given an explanation on how to repair the edges of a kendo mask, and this time we learned about indigo dyeing.

Indigo dye remake Dye trivia

露木"There are many different dye solutions available on the market, so you can use any of them to find the color you like when you do it yourself, but the first thing you need to do is wet it. You can use a spray bottle, so just spray it on. The reason you need to wet it is that it causes the fibers to swell, or if you apply it once to the parts that have opened up, they will tighten up when they dry, making it easier for the dye to penetrate.

露木"When dyeing with Kensen, you always wash it first. That is, while you are washing, you do the first step of the dyeing process. This is before you add the dye. You can paint it while it is dry, but the point is that the dye doesn't adhere well if you paint it on something that is dirty, so you need to wet it once to swell the fibers, spread it out, and then apply the first coat. Then, once it dries, apply the second coat. You can do this with a brush. If possible, it's good to apply three coats. By the third coat, you can correct any slight color unevenness, so I think if you apply three coats, it will come out nicely even if you paint it yourself. Even with Kensen, you apply at least two to three coats. But the first coat is when you add the color while it's still wet."

露木"So, does this bother you? Does it bother you?"

露木"This (liquid A) is going to be discarded today and can no longer be used as indigo. And this (liquid B) is a fresh indigo. Can you tell that the colors are different?

露木"B liquidLiquid A is more green or yellowish brown. Liquid A is blue. Liquid A seems to take on color better somehow."

──Yes, I think so.

露木"But, Liquid A is already dead, so the color doesn't really stick."

──Liquid A seems to have more color.

露木"It's kind of like ink, which is nice. Liquid A seems to have more color, I think."

──Yes, that's right.

露木"B liquidThen, because we use natural indigo, the color is completely different."

──You mean transparency?

露木"That's right. The smell is the same, too. Liquid B has a bit of a smell. It smells like mud."

──Wow

露木“Liquid AIt doesn't smell that bad"

──I don't use Liquid A very often.

露木"B liquidIt's already intense."

──That's intense.

露木"Wow."

──Does this lead to increased collusion?

露木"That's right. It's like Solution B is more alive, or rather, this solution itself is in a state of oxygen deprivation.

With natural indigo, bacteria ferment it, creating an oxygen-free environment. We also use natural indigo, but the oxygen inside is removed chemically."

露木“Liquid AIt's already full of oxygen."

──I see.

露木"That's right. You can see the difference. Liquid B is more energetic."

露木"So, it's interesting. You add a coloring agent. You can use water, or even air, but actually it's fine.

Solution A doesn't change, but if you add this to solution B..."

──Oh!

露木"At this point, the color really comes out.

──Wow

──Huh? Is this water?

露木"This is a chemical called a color fixative, but water has the same effect. Would you like to try again?

--Is it a chemical change or something?

露木"Indigo takes on the color of oxygen in an oxygen-free environment."

──What is indigo dyeing like?

露木"That's right. Indigo dyeing is done by oxidizing it in air and adding water.

露木"Maybe it just gets diluted with water. Oh, so water doesn't work after all. But can you see that it's a little blue?"

──Ah, yes.

露木"If you mix this together, it gradually becomes..."

──It's gotten darker.

露木"It gets darker. This is the kind of situation we create on the fabric."

露木"The previous one is more interesting. There is something called a color fixative. I think it's probably an acidic one."

──Are there any color fixing agents?

露木"That's right. You can use either plain water or air. Indigo turns bluer when it comes into contact with air."

露木"Even a single drop of indigo produces a vibrant color like this."

露木“Liquid AIt doesn't change at all."

露木"So, if you apply it when it's this color (the color it is when Liquid B reacts), and leave it, it will gradually turn blue as it comes into contact with the air. Even indigo can have a range of colors, from reddish to this navy blue. Even hakama often have a slightly reddish tint."

──Ah, yes, there is.

露木"When the indigo is young, it's red, and then it gradually turns blue. But once it turns blue like Liquid A, it doesn't dye anymore, or rather, the color doesn't stick. It turns into Liquid B, and when you let the color come out on the fabric, it adheres well, or rather, it fixes well."

露木"B liquidIt takes 10 days to 2 weeks for the color of Liquid A to change from Liquid A to Liquid B. Once that happens, Liquid A can no longer be used. So, the process is to paint it while it is still Liquid B and let the color develop.

--Do you apply this liquid to the hakama and other garments, and then add the color fixative?

露木"We don't dye hakama or training clothes. It's a lot of work. Usually, dye shops will dip the thread in indigo liquid, wring it out, wash it with water, and dip it again, and repeat the process. There are various methods, such as lining up tubs of dye and dipping the thread in more and more to make it darker. In Kyoto, I saw a roll of fabric being poured into a tub of dye, and when it came up, it was initially the same color as the indigo liquid, but as time passed, it turned bright blue. I realized that this is the principle by which the color takes hold."

露木"But what about the ones on the market? There may be some that already contain coloring agents, so you can just apply them as they are."

──Do you paint this with a brush or something?

露木"We'll blow everything away, whoosh."

--Oh, so you don't paint it?

露木"Yes, it's a machine bigger than a peace gun, and it goes whoosh."

──Spray it all over?

露木"Yes, you spray it all over. Then your hands turn blue. But it just keeps falling off. It would be nice if we could stop this, but it's probably difficult to completely stop it at the moment.

Developing a chemical to prevent color fading

--There is something called an indigo dye stopper, right? Isn't that effective?

露木"I've tried a variety of chemicals, some of which stop the dyeing while washing, removing the stains while minimizing the release of color, and some which stop the dyeing beforehand. However, the point is that they only slow down the speed at which the indigo dye is stopped, they don't stop it completely. The indigo dye sits on top of the fibers, and then a coating is applied on top of that, so the indigo dye-stopping chemicals work."

--So in that sense it is effective?

露木"It is effective. However, it doesn't mean that the indigo dye won't come off completely, but rather that it slows down the process. However, if you use soap with bleach in it, the indigo dye will gradually come off, so if you wash your hands with an indigo dye inhibitor, the effect will remain and the fading will slow down. I don't think it will completely come off, though."

露木"I'm making that too now."

──I see.

露木"We are currently making chemicals for use at the beginning, for use when rinsing, and for processing the fabric to make it soft and supple."

──Do you want to sell it?

露木"I want to sell it, of course."

Natural indigo is alive

This time, we were given an explanation about indigo dyeing.

Click here for the explanatory video →　https://www.youtube.com/watch?v=LYpP_OBZ89c&t=8s

I thought the bright blue dye would produce more color, but I was surprised to see that when mixed with the color former, the light green indigo liquid turned into a richer indigo blue.

This chemical mechanism has been known for a long time, and I felt deeply the profoundness of tradition, and felt that if possible, it is something that we should cherish forever.

Next time, as a conclusion to this Ken-washing series, we would like to get some advice from a kendo equipment maintenance professional.

looking forward to!

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