I have a bamboo fence in my front yard, and during covid it got pretty gray and worn out looking. Coating it with oil helped it weather the elements, but it did not look very attractive.
I had wondered for a long time about traditional outdoor pigments in Japan. I had seen references to a black paint for castles, and Ishiyama and I had discussed what exactly it might be. There’s a shortage of eco-friendly outdoor paints; most of the worst finishes I use are all outdoor. So I set out to do some research, and discovered shibuzumi / 渋墨、persimmon ink paint.

Shibuzumi was used to paint the castles of Japan in the Edo period, as well as some of the walls and faces of houses and storefronts throughout the cities. It is a mixture of bengala, pine soot, and kakishibu/persimmon tannin.

It is sticky, and comes off a bit when you rub against it, so it is not ideal for something interior like furniture. It was used to paint floors and I did find instructions on how to do it, but it seems like it would be very messy and rustic.

The exact origin of the paint, and how far back it was used, I could not find. This is an area that merits some further research. Many of the existing pre-Edo castles have been renovated if they survived, so one would have to look through era scrolls and paintings to see if the castles were painted black.

Making Shibuzumi

You can actually order shibuzumi from amazon.jp, or the manufacturer’s website directly. However, and I learned this the hard way, Rakuten and other forwarding services cannot ship the paint to the US because of customs restrictions.

But what you can ship are the ingredients to make the paint. I imagine many of these ingredients or their equivalents can be found outside of Japan. At the time, I ordered during the COVID crisis and shipping prices were fluctuating wildly and Rakuten kept sending out 50% off coupons, so I didn’t worry too much about the price for a small project. For a large project, sourcing locally would probably be ideal. Persimmon tannin and persimmon tannin powder are both widely available in the states, and the closest thing to pine soot is probably what we would call “lampblack”. Iron oxide can be found from dyer’s websites if not somewhere else.

Shopping List

1. Pine Soot / Matsu Kemuri /松煙 (Pine Soot)
2. Bengala / ベンガラ 弁柄 (Iron Oxide)
3. Kakishibu / 柿渋
4. Perilla, linseed or another plant oil. I used Tried & True’s Danish Oil, which is hydrogenated to keep it from going rancid, but still nontoxic. I remember reading that the Japanese use perillia oil mainly because of the lack of availability of other finishing oils like linseed, which has a superior chemical composition but is not cultivated in Japan as much.
5. Clear Alcohol, of some form. The traditional recipe uses shochu, because it’s cheap. I had everclear on hand for dissolving wood finishes, so I used that. I don’t remember exactly how much I used, because I used it reactively to dissolve the pine soot.

Recipe

I really recommend you mix this outside, somewhere black or dirt, like your driveway or lawn. Wear a mask, there’s a lot of fine powders, and gloves.
The container you use to mix the paint is is going to be permanently covered in ink soot that won’t come out, so something cheap and disposable is recommended for that as well.

I got my recipe from here, and the author has pictures of their own process as well.

Ingredients

• 750g Pine Soot
• 300g Bengala
• 50ml Linseed/Perillia Oil
• 700ml Water
• 1 cup of cheap clear alcohol, dilute if high proof

Instructions

• Dissolve the pine soot in the alcohol (diluted if high proof). Basically, you want a thick paste. Try adding a bit gradually and stirring, then adding some more. The alcohol should dissolve the clumps of pine soot.

• Add the kakishibu. You may need to add more water if you just bought kakishibu powder.

• Add the bengala. The amount of bengala you add determines how red your paint is, so if you want a more brown paint, then you need to add more.

• Add the oil. Mix thoroughly.
• Your paint is ready! Take it out to your surface and apply it. Because of the alcohol in the paint, you may want to use a natural hair brush. Get a cheap brush, because it will not wash out.

Results

This was a very messy process, so I’m glad I mixed it outside. I also noticed that my paint, which I mixed in batches, was slightly unevenly colored, with more brown in some places than others. With a few coats, it evened out, but if I was doing this on a something more important than a garden fence, I might have been alarmed.

Eventually, I got a very black fence, which is what I wanted. Once it dried, I covered it in a few layers of danish oil. The paint held up decently for one winter, but clearly needed to be repainted. Because I was ill, I didn’t have the chance to repaint it, and after two years, it really did not look very good at all, and I took the fence down because it had deteriorated. It seems like the kind of coating that needs a lot of upkeep, but if you have a castle, that’s probably not a big deal.

Overall, I didn’t think it was worth the cost and trouble for my application, but it was fun to try a historical method.

References & Further Reading

• Shibuzume Manufacturer
• Oyama Sawmill
• Lacquerware made with Shibuzumi
• Shibuzumi Recipe
• Bengala/Iron Oxide
• Pine Smoke
• Kakishibu Powder