A Step-by-Step Guide

Creating an indigo dye vat is an excellent way to upcycle clothing and fabrics, giving them a new lease on life with beautiful, rich shades of blue. This traditional dyeing technique not only revitalizes old garments but also reduces waste and promotes sustainable fashion practices. Using soda ash, hydro sulphite, and indigo powder, you can create a traditional indigo vat at home. Here’s a detailed guide to help you through the process.

Materials Needed:

Indigo Powder
Soda Ash (Sodium Carbonate)
Hydro Sulphite (Sodium Hydrosulphite)
Warm Water
A Non-Reactive Container (Plastic or Stainless Steel)
A Stirring Stick or Spoon (Non-Reactive)

Safety Precautions:

Wear gloves and protective eyewear.
Work in a well-ventilated area.
Avoid inhaling the powders.

Amounts for Different Vat Sizes:

2-Liter Vat: Up to 15 pieces (depending on the sizes of the garments)

Indigo Powder: 10 grams
Soda Ash: 2 tablespoons (approximately 30 grams)
Hydro Sulphite: 2 tablespoons (approximately 30 grams)
Warm Water: 2 liters

5-Liter Vat: Up to 25 pieces (depending on the sizes of the garments)

Indigo Powder: 25 grams
Soda Ash: 5 tablespoons (approximately 75 grams)
Hydro Sulphite: 5 tablespoons (approximately 75 grams)
Warm Water: 5 liters

10-Liter Vat: Up to 50 pieces (depending on the sizes of the garments)

Indigo Powder: 50 grams
Soda Ash: 10 tablespoons (approximately 150 grams)
Hydro Sulphite: 10 tablespoons (approximately 150 grams)
Warm Water: 10 liters

Step-by-Step Instructions:

Preparation:

Prepare the Indigo Paste:
- Measure the indigo powder based on the size of your vat. For a small vat, start with 10 grams of indigo powder.
- Mix the indigo powder with a small amount of warm water to create a smooth paste. This helps the indigo dissolve more easily in the vat.
Dissolve the Soda Ash:
- In your vat container, add warm water (about 50°C or 120°F). The amount of water depends on your vat size; for a 2-litre vat, use 2 litres of water.
- Add soda ash to the warm water at a ratio of 1 tablespoon per liter. For a 2-liter vat, use 2 tablespoons of soda ash. Stir until completely dissolved. The soda ash creates the alkaline environment needed for the indigo to reduce.
Add the Indigo Paste:
- Add the prepared indigo paste to the soda ash solution. Stir gently to avoid introducing too much oxygen.
Dissolve the Hydro Sulphite:
- In a separate container, dissolve sodium hydrosulfite in warm water (same temperature as above) at a ratio of 1 tablespoon per liter. For a 2-liter vat, use 2 tablespoons of hydro sulphite. Stir until completely dissolved.
Combine the Solutions:
- Slowly add the dissolved hydro sulphite to the vat container while stirring gently. Hydro sulphite acts as a reducing agent, removing oxygen from the vat and converting the indigo to its soluble leuco form.
Let the Vat Rest:
- Allow the vat to rest for 15-30 minutes. During this time, the indigo should reduce, turning the solution a yellowish-green color, indicating it is in its soluble form.

Images: * All measurements based on a 10L Vat

Indigo Powder
Indigo Paste
Soda Ash
Hydro Sulphite

Using the Vat:

Pre-Wet Your Fabric:
- Before dyeing, thoroughly wet your fabric to ensure even dye absorption.
Dyeing Process:
- Submerge the fabric in the vat slowly to minimize oxygen introduction. Stir the fabric gently in the vat for about 1-2 minutes.
- Remove the fabric slowly and let it oxidize in the air. The color will change from yellow-green to blue as it oxidizes.
- Repeat the dipping and oxidizing process until the desired shade of blue is achieved.

Images:

Indigo Vat with healthy ‘Flower’ (The dark, opaque blue 'flower' that sits atop an indigo vat is oxidized indigo - a molecule that will not dye fabric)
Colour after first dip before it starts oxidising
Colour after first dip after it oxidises
Second dip in the vat
Third dip in the vat
Clothing showing the different stages of the indigo vat
Up-cycles dress dyed in indigo

Maintaining the Vat:

Check and Adjust:
- If the vat isn’t used frequently, it might need to be "fed" with more soda ash and hydro sulphite to maintain proper conditions. Add small amounts and check the color regularly.
Storage:
- Keep the vat covered when not in use to minimize oxidation and contamination.

How to Care for Your Indigo-Dyed Clothes

Indigo-dyed clothes are beautiful, timeless, and unique, but they require special care to maintain their vibrancy and quality. Here’s how to take care of your indigo-dyed pieces to ensure they last for years to come.

1. First Wash Care: After dyeing, it’s important to rinse your indigo-dyed fabric thoroughly. The first few washes may release excess dye, so wash your garment separately from other clothes. Use cold water and a gentle detergent to minimize colour fading. Avoid using bleach or any harsh chemicals.

2. Hand Wash or Gentle Cycle: For the best results, hand wash your indigo-dyed clothes in cold water with a mild, pH-neutral detergent. If you prefer to use a machine, choose the gentle cycle, cold water, and place the item in a mesh laundry bag to reduce friction.

3. Air Dry: Avoid the dryer, as the heat can fade indigo over time. Instead, air dry your clothes in the shade. Direct sunlight can also lead to fading, so hang them in a cool, shaded spot.

4. Avoid Frequent Washing: Indigo-dyed clothes don’t need to be washed after every wear. Spot clean when necessary, and air out your garments between uses to keep them fresh. The less you wash, the longer the colour will last.

5. Store with Care: Store your indigo-dyed clothes in a cool, dry place away from direct sunlight. This will prevent fading and keep your pieces looking vibrant.

By following these simple steps, you’ll be able to enjoy the rich, deep hues of your indigo-dyed clothes for years to come.

Creating and maintaining an indigo dye vat is a rewarding process that allows you to explore the beautiful world of natural dyeing. By following these steps and adjusting the amounts based on your vat size, you can achieve vibrant and lasting shades of blue on your fabrics. This technique is a fantastic way to up-cycle and breathe new life into old garments, promoting sustainability and reducing waste. Happy dyeing!