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

Tsuyuki : " There are many different dye solutions available on the market, so you can use any of them to find the color you like, 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 as they dry, making it easier for the dye to penetrate."

Tsuyuki : " When dyeing with Kensen, you always wash it first. That is, while you're washing, you do the first step of the dyeing process, before adding the dye. You can paint it while it's dry, but the point is that the dye won't adhere well if you paint it over something that's dirty, so you need to wet it once to swell the fibers, spread it out, and then apply the first coat. Then, once it's dry, apply the second coat. You can do this with a brush. If possible, it's good to paint three coats. By the third coat, you can fix any slight unevenness in the color, so I think if you paint it three times, 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."

Tsuyuki : " So, does this bother you? It bothers you, doesn't it?"

Tsuyuki : " 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 it's a different color?"

Tsuyuki : "Liquid B is more green, or maybe yellowish brown. Liquid A is blue. Liquid A somehow seems to take on color better."

──Yes, I think so.

Tsuyuki : " But the A liquid is already dead, so the color doesn't really stick."

──Liquid A seems to have more color.

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

──Yes, that's right.

Tsuyuki : "The B liquid uses natural indigo, so the color is completely different."

──You mean transparency?

Tsuyuki : " That's right. The smell is the same. Liquid B has a bit of a smell. It has a muddy smell."

──Wow

Tsuyuki : "Liquid A doesn't smell that bad."

──I don't use Liquid A very often.

Tsuyuki : "Liquid B is really strong."

──That's intense.

Tsuyuki: " Ohhh"

──Does this lead to increased collusion?

Tsuyuki : Right. It's like Liquid B is more alive, or rather, the liquid 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."

Tsuyuki : "The oxygen in Liquid A has already been absorbed."

──I see.

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

Tsuyuki : " So, it's interesting. You add a coloring agent. Water would be fine, or even air would be fine.

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

──Oh!

Tsuyuki: " At this point, the color really comes out."

──Wow

──Huh? Is this water?

Tsuyuki : " This is a color-fixing agent, but water has the same effect. Shall we try again?"

--Is it a chemical change or something?

Tsuyuki : " Indigo takes on color when oxygen is present in an oxygen-free environment."

──What is indigo dyeing like?

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

Tsuyuki: " I guess it just gets diluted with water. Ah, water doesn't work after all. But can you see that it's a little blue?"

──Ah, yes.

Tsuyuki : " When you mix this, it gradually..."

──It's gotten darker.

Tsuyuki : " It gets darker. We create this kind of situation on the cloth."

Tsuyuki : " The previous one was more interesting. There's something called a color fixative. I think it's probably acidic."

──Are there any color fixing agents?

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

Tsuyuki : " Even a single drop of indigo creates such a vibrant color."

Tsuyuki : "Solution A remains unchanged."

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

──Ah, yes, there is.

Tsuyuki : " Well, when the indigo is young it's red and gradually turns blue. But once it turns blue like liquid A, it doesn't dye anymore, or rather the color doesn't stick. It becomes like liquid B, and when you let the color come out on the fabric, it adheres well, or rather, it stays in place well."

Tsuyuki : "The color of Liquid B changes to the color of Liquid A in 10 days to 2 weeks. When that happens, Liquid A can no longer be used. So the process is to paint it while it's still the color of Liquid B to make it develop."

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

Tsuyuki : " We don't dye hakama or training clothes. It's a lot of work. Usually, dye shops will dip the thread in indigo, wring it out, rinse it in water, and dip it again, and repeat the process. There are various methods. For example, they may line up tubs filled with dye and dip the thread in more and more until the color becomes darker. In Kyoto, I saw a method where rolls of fabric were floated into a tub filled with dye, and when they came up, they were initially the same color as the indigo liquid, but as time passed, they turned bright blue. I realized that this is the principle by which the color takes hold."

Tsuyuki : But what about the products on the market? Maybe some already contain coloring agents, and you just apply them as they are.

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

Tsuyuki: " I'll blow it all away, with a whoosh."

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

Tsuyuki : " Yes, it's a machine bigger than a peace gun, and it makes a whoosh."

──Spray it all over?

Tsuyuki : " 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 I think it's 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?

Tsuyuki : " I've tried a variety of different things, including chemicals that stop the dye from fading, some that stop the dye as you wash the fabric, removing the stains while minimizing the release of color, and some that stop the dye before it fades. However, these only slow down the speed at which the dye stops, 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 with chemicals that stop the dye from fading."

--So in that sense it is effective?

Tsuyuki : " It is effective. However, it doesn't mean that the indigo dye won't come off completely, but rather that it does come off more slowly. However, if you use soap with bleach in it, the indigo dye will 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."

Tsuyuki : " I'm making that right now too."

──I see.

Tsuyuki: " We're currently making chemicals for use at the beginning, for washing, and for processing to make the fabric soft and supple."

──Do you want to sell it?

Tsuyuki : " Of course you want to sell it."

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.

Stay tuned!

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