Traditionally, natural dyeing has been used by ancient people to extract and use color-expressing substances from flowers, fruits, leaves, roots, barks, animals, minerals, seaweed, fungi, mushrooms, and mosses that contain beautiful colors. In the past, most dyeing dyes were plant dyes, and among them, indigo dye was the most widely used. It was generally used to dye vegetable fibers, but it also dyes well on animal fibers such as silk and wool, and became a dyeing method in daily life and traditional crafts.

The word "Nam" (藍) does not simply refer to a plant, but is a general term for plants that contain the pigment "Nam" (藍). In literature from Korea, China, and Japan, it is recorded as "Nam" (藍), but traditionally, it was called "Jok" or "Jjokmul" in Korean. Indigo was introduced from India and Egypt, and then crossed over to China, Korea, and Japan. Judging from the use of the phrase "靑出於藍" (靑 comes from "Nam" (藍) and is bluer than "Nam" (藍); meaning a disciple who is more outstanding than his teacher) in the Chinese literature of the 3rd century BC, it can be known that indigo was used before the 3rd century BC.