Sagyeongjang can refer to either the art of copying Buddhist texts or to the masters of this art. Sutra copying enjoyed its heyday during the Goryeo Dynasty when Buddhism gained widespread popularity. During the reign of King Chungnyeol, the Goryeo court dispatched to China hundreds of Buddhist monks trained in sutra copying. Although sutra copying declined during the Joseon era with the adoption of Confucianism as the governing philosophy, the Buddhist practice lived on with the support of certain royal family members and Buddhist temples. The ink transcription of the Avatamsaka Sutra (Flower Garland Sutra) from the Unified Silla era, designated National Treasure, is the oldest surviving artifact in Korea testifying to the sutra copying practice.

The art of sutra copying is generally comprised of three parts: transcribing text, reproducing byeonsangdo paintings, and decorating the cover with a design of Buddhist figures or plants. It is further divided into 10 different steps: color formation with gold powder, glue making, surface treatment of the paper, paper cutting, connecting paper sheets, line drawing, writing text by hand, drawing byeonsangdo paintings, decorating the cover with a drawing, and treating the cover with gold powder. It demands expert knowledge of calligraphy, Chinese characters, Buddhist theory, and painting. Furthermore, intense concentration over long periods is essential.

* Sagyeong (寫經): The practice of transcribing Buddhist scriptures or the resulting transcripts. Sutra copying is intended to disseminate Buddhist texts or cultivate merit.
* Byeonsangdo (變相圖): Paintings illustrating the teachings of the Buddha