Dye: Cutch (Katha) or Walnut hulls
Color: Rich dark browns
Color Fastness: Excellent wash and light fastness on cotton, silk, and wool
A. Cotton Dyeing Procedure (Ground Coffee / Cutch)
Step 1: Mordanting
- Material: 100 g cotton
- Mordant: Alum 10% owf (10 g)
- Water: 2 L (M:L 1:20)
- pH: Neutral (~6-7)
- Temperature: 55°C
- Time: 45 minutes
Process:
- Dissolve 10 g alum in 2 L water at 55°C.
- Add cotton fabric, stir gently for 45 minutes for mordant uptake.
- Remove fabric, rinse lightly with cold water.
Reason: Alum mordant binds well with cotton cellulose and enhances brown hues from cutch. Alum is preferred over iron here to get warm brown tones instead of olive or greyish.
Step 2: Dye Extraction & Dyeing
- Dye: Cutch powder 15% owf (15 g) or ground walnut hulls
- Water: 2 L
- Temperature: 80°C (near simmer)
- Time: 60-90 minutes
- pH: Neutral to slightly acidic (~6)
Process:
- Boil water, add cutch or ground walnut hulls, simmer gently for 60 minutes to extract dye.
- Strain the bath to remove solids.
- Cool bath to 75-80°C, add mordanted cotton fabric.
- Maintain temp, stir gently for 60-90 minutes.
- Remove fabric, rinse cold, dry in shade.
Reason: High temperature and long dye time maximize dark brown pigment extraction. Walnut hulls and cutch have tannins that bond well with alum-mordanted cotton.
B. Silk Dyeing Procedure (Ground Coffee / Cutch)
Step 1: Mordanting
- Material: 100 g silk
- Mordant: Alum 8% owf (8 g)
- Water: 2 L (M:L 1:20)
- Temperature: 50°C
- Time: 30 minutes
Process:
- Dissolve 8 g alum in warm water at 50°C.
- Add silk fabric, stir gently 30 minutes.
- Remove and lightly rinse silk.
Reason: Silk needs lower mordant concentration and temperature to protect fiber integrity.
Step 2: Dyeing
- Dye: Cutch powder 12% owf (12 g) or ground walnut hulls
- Water: 2 L
- Temperature: 65°C
- Time: 60 minutes
- pH: Neutral (~6)
Process:
- Simmer dye material for 45 minutes, strain.
- Cool bath to 65°C, add silk fabric.
- Stir gently for 60 minutes.
- Remove, rinse cold, air dry in shade.
C. Wool Dyeing Procedure (Ground Coffee / Cutch)
Step 1: Mordanting
- Material: 100 g wool
- Mordant: Alum 8% owf (8 g)
- Water: 2 L
- Temperature: 50°C
- Time: 30-40 minutes
Process:
- Prepare alum mordant bath at 50°C.
- Immerse wool, gently stir 30-40 min.
- Remove wool, rinse lightly.
Step 2: Dyeing
- Dye: Cutch powder 12% owf (12 g) or walnut hulls
- Water: 2 L
- Temperature: 60°C
- Time: 60 minutes
- pH: Slightly acidic (~5.5-6)
Process:
- Extract dye at simmer.
- Cool bath to 60°C, dye wool for 60 minutes.
- Remove, rinse cold, dry flat in shade.
Summary of Parameters (Ground Coffee / Cutch Dyeing)
Reasoning Highlights:
- Alum mordant is chosen for warm, rich browns from cutch/walnut hulls.
- High dye bath temperature improves pigment extraction for cotton.
- Silk and wool require gentler temperature and mordant concentration.
Neutral to slightly acidic pH preserves fiber and dye stability