Indigo Dyeing in Thailand

Dyeing with indigo is a craft that has been passed down from generation to generation in Thailand.

The process begins with the planting of indigo plants in households. At harvest time the collected indigo plants are fermented using a mixture of ash, red lime and other ingredients to make it into indigo paste. 

This resulting indigo paste can be stored in a container for more than a year. The indigo that will be used to make the pot for dyeing fabric must be cooked first. In order to make an indigo pot, a base such as ash is required as well as a sugar such as tamarind fruit and red lime. Some of these ingredients used are also used in Thai cooking. Each area can use slightly different ingredients. The pH has to be managed as the vat needs to be a base. Indigo vats require regular care and need to be fed fresh ingredients in order to maintain a healthy vat and give beautiful, deep colors.

Raw materials used to make indigo vats and indigo seeds

Making a good indigo vat to gives deep blue color is quite difficult. It requires a lot of knowledge and expertise. It also depends on many external factors such as temperature, humidity, water quality, and many others.

A complete indigo pot ready for dyeing fabric.

The intensity of the resulting blue color depends on the number of dips into the indigo vat. The darkest colors can require more than 10 dips.

To get a dark color, it is necessary to repeat the dye process several times.

Indigo dyeing is different from other natural dyeing methods. Indigo doesn't need to rely on other substances such as mordants that help the dye stick to the fibers. It also doesn't need any heat so there is no need to heat big vats such as with other dyeing methods. Once the color is as preferred, the fabric can be washed with a gentle laundry detergent.

Genuinely indigo dyed fabric often still has a scent of the indigo process, which is a quite a unique scent. If you have received freshly dyed fabric you can tell wether it is real indigo by smelling: if it has a slightly earthy, tangy odor you be sure it is real indigo dyed fabric. It is the smell that might remind you of a farmhouse at the end of a fertile rice field.