Sukumo Japanese Indigo Dye

Description

Sukumo is the traditional Japanese form of natural indigo dye, made from the dried and composted leaves of Persicaria tinctoria (Polygonum tinctorium), known as Japanese indigo or tadeai. Through a months long fermentation, the leaves become a rich composted dyestuff that is the heart of the Japanese aizome (indigo dyeing) tradition. In a fermentation vat or a reduced vat, sukumo yields shades of deep midnight blue, smoky steel, and bright sky blue, depending on the number of dips and the fiber. Sukumo dyed fabrics are prized for their depth, softness, and a distinct hand feel unique to this heritage method.

Recommended Use

Use in a fermentation vat or a reduced vat with an alkaline agent (such as wood ash lye, soda ash, or lime) and a reducing agent (like wheat bran, sake, fructose, or thiourea dioxide). Works beautifully with multiple dips to build color and fastness. Ideal for cotton, linen, silk, and wool. Sukumo excels in resist dyeing (katazome, shibori) and traditional stencil work.

Historical Significance

Sukumo lies at the heart of Japan's indigo culture, with Japanese indigo grown in Japan for well over a thousand years. During the Edo period (1603 to 1868), aizome became a symbol of everyday beauty, artisan craft, and rural life. Indigo farmers, most famously in the Awa region of Tokushima, made sukumo by piling, watering, turning, and aging the leaves through the winter to produce a high quality dyestuff. Indigo became so central to Japanese life that it was called "Japan Blue," seen in everything from workwear and kimono to festival banners.

Dye Details

Name: Indigotin from fermented Persicaria tinctoria
Origin: Tokushima Prefecture, Japan (traditional source)
Dye Type: Fermented botanical compost
Recommended Fibers: Cotton, linen, silk, wool, hemp, and bast fibers
Lightfastness: Excellent on all natural fibers
Vat Components (for sukumo fermentation vat):
Sukumo (20 to 30 g/L starting)
Alkaline base: wood ash lye or soda ash
Natural reducer: wheat bran, sake, or fructose
Heat and time: hold at 77 to 95°F (25 to 35°C) for vat fermentation over several days
Modifiers for tone control:
Dip duration and frequency
pH balance
Reduction strength

Packaging

Available in resealable, eco friendly kraft pouches with detailed vat setup instructions for both natural and quick reduction methods. Hand harvested and fermented by Japanese indigo farmers using traditional techniques.

Health and Safety

• For art use only. Not for cosmetic, food or children's use.
• Keep out of reach of children and pets. Do not eat, drink or smoke while working.
• Avoid creating or breathing dust. Work in a ventilated area and wear a NIOSH approved dust respirator (N95 or better) when handling dry pigment.
• Wear gloves and eye protection. Wash hands and work surfaces after use, and never rinse pigment into drains.
• Do not spray apply, sand or burn.
• If swallowed or if you feel unwell, contact a poison control center (U.S. 1-800-222-1222) or a doctor.
• Safety Data Sheet available on request.