I'm using it a little. Made by Cao Sugong. This ink is also known to have been specially ordered by Tomioka Tessai, a Japanese painter and calligrapher. (Antique ink) I am looking for someone who understands this item. This is from my older brother, who has been practicing calligraphy for over fifty years. Most of these items were purchased and stored decades ago. I am listing them at his request. It seems that both inkstones, paper, and ink improve with age, but it's all Greek to me? There are too many items, and it takes time to research them. I will be listing them little by little, so I would be happy if you could take a look when you have some free time. Thank you for looking.