Back to the workshop, Flora started by showing us how to make an indigo vat. I learnt that Flora uses Michel Garcia's organic 1-2-3 method to create her indigo vats, as described by Botanical Colors below:
"Michel’s technique, which is based on the traditional indigo vats of Morocco, India and Provence, relies on the chemical reactions between a mineral alkali and a natural reducing agent to remove excess oxygen (a chemical process called reduction), which liberates the indigo dye molecule, allowing it to attach to fibers and bond." (Botanical Colors, 2017, online).
The recipe is as such:
- 1 part powdered natural indigo
- 2 parts calcium hydroxide, also known as lime
- 3 parts fructose crystals
She maintains her vat by adding more of this mixture every now and then, and also reclaims the used indigo powder by sifting the rinse water through a muslin so that it can be used again. This is not only great from a sustainability perspective, but also a financial one! Indigo does not require a mordant to fix to the fabric, which reduces preparation time and the need for more chemicals.
After learning some basic shibori techniques with wooden blocks, clamps and pegs, we set about to dipping our fabric in the vat. As with dyeing with woad, the fabric is dipped into the vat for a minute, then carefully removed, so that the fabric can oxidise and turn from green ton blue, before dipping any number of further times. The resist worked My knitted fabric worked much better than expected, and after a couple of dodgy attempts I began to get the hang of the technique.