Natural indigo has been considered a valuable blue dyeing material for centuries. It can be extracted from the fiber of several different plants.

In Japan, the only useable indigo plant is polygonum, which is well-known for its outstanding deep color.

Fermented polygonum, the dye pigment, is
called "sukumo."

In addition to the "sukumo," wheat husk powder, limestone powder, lye ash, and sake are also mixed into the vats to complete the liquid dye.

Then for approximately a week, the dye naturally begins to ferment until it reaches its usable state.

Indigo threads and materials--specifically cotton and linen--are generally soaked and dried 15 to 20 times.

Silk, on the otherhand, must be soaked and dried 40 to 45 times.

This is the only way to deepen the color.

The dyed thread and materials are sun-dried, which is when the deep indigo blue appears most strongly on the fiber surface.

Indigo also strengthens the material.
Indigo dyeing is considered one of the most beautiful dyeing techiniques known to man.

Indigo dyed materials soften with use, and the quality of the color's richness increases with time.