How did Inoue Kazuyuki make ink?

One of the wells used carbon black powder and water-based adhesive. I tried, but it didn't work. It is estimated that there are many kinds of carbon black and its properties are also problematic. Later, I tried to use iron hydroxide, and the effect was better, but I still didn't feel that way. There is a research called Zhao Xucheng in China, but he doesn't want to make it public. He wants to apply for a patent. His handwriting is a bit tacky, but it can still fetch a good price.