Kihada [Powerswood]

Kihada

The Japanese name means "yellow skin" because the inner bark between the resinous outer skin and the internal woody part is a bright yellow color.
When the cork and outer bark are removed from the bark and the inner bark is dried, it becomes the herbal medicine Obaku, which can be harvested after about 20 years of age. It is mainly used as a bitter stomach tonic, intestinal regulator, and pharmaceutical ingredient, and is included in medicines such as Dharanisuke and Hyakuso. It is also used as a dye, and there was a time when it was used to dye paper for Buddhist scriptures, hoping that it would prevent insects from eating it.
Immediately after dyeing, it has the effect of making the ink-written characters stand out, and over time it turns brown, but existing documents from the Shosoin Repository and the "Gyoyo Sutra" handed down from Yakushiji Temple are all dyed using this method.

The inner bark between the outer bark and the inner woody part is bright yellow, which is why the Japanese name comes from the meaning "yellow skin."
When the corky and outer bark is removed from the bark and the inner bark is dried, it becomes the medicinal yellow oak, which can be harvested when the tree is about 20 years old.
It is mainly used as a bitter stomachic, intestinal regulating agent, and as a pharmaceutical raw material, and is included in medicines such as Daranisuke and Hyakuso.
It was also used as a dye, and there was a time when it was used to dye paper for Buddhist scriptures in hopes of preventing insect bite. Immediately after dyeing, it has the effect of making the ink calligraphy stand out, and although it has turned brown over time, the existing Shosoin documents and the "Gyoyo Sutra" handed down at Yakushiji Temple are the result of this dyeing.