This is an invitation to let this unique woad be what it is – without comparisons or expectations. Our unofficial strapline is ‘slow, difficult and expensive’ for a reason.
Natural textile dyeing takes skill, which takes time and practice to develop. Of the many natural dyes, indigo is the most challenging and in comparison to other sources of indigo, woad yields less pigment and gentler shades – which for some, will make it even more challenging! Growing indigo commercially in the U.K. is also difficult and producing pigment while adhering to organic principles means this is a rare and precious blue indeed, doing its best to blaze a trail for regenerative textiles. This kit will not make you an instant expert, neither are there any guarantees you’ll master the process first time, but if you follow the instructions and video tutorials below, you may find yourself initiated by this wise, old colour.
Making a woad indigo vat
This recipe creates a ‘Mother Vat’ or stock solution. We recommend using this for small, tie-dyed fabric or yarn dyeing projects.
EQUIPMENT
- rubber gloves, mask & apron
- 3 litre mason jar
- pestle & mortar
- long handled spoon
- small glass or egg cup
- weighing scales
- scoured fibre e.g. a white T-shirt
HEALTH & SAFETY
natural DOES NOT = safe
and
chemical DOES NOT = bad
(everything is chemical!)
When you practice natural dyeing, you are practicing chemistry, whether you choose to study it at that level or not. Granted, most natural dyes are more environmentally friendly but in much the same way as we wouldn’t eat any plant we came across, we must ensure precautions are taken when dyeing with so-called ‘natural’ substances. You are solely responsible for researching the materials you use but following these guidelines is advisable:-
- allocate pots, containers and utensils for dyeing and don’t use these for food preparation afterwards
- Wear rubber gloves, apron and face covering (when measuring fine powders)
- Calcium Hydroxide (builder’s lime) is a fine powder alkali that carries the following warnings:- Causes skin irritation. Causes serious eye damage. May cause respiratory irritation. Avoid breathing dust/fume/gas/mist/vapours/spray. Wear protective gloves/protective clothing/eye protection/face protection. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
MAKING AN INDIGO VAT
- Wear apron, gloves and mask.
- Grind your indigo powder in the pestle & mortar, with enough hot water to make a smooth paste, for at least 10 minutes.
- Mix in more hot water so you can pour solution from mortar to mason jar.
- Add hand hot water to half-fill jar and test pH.
- In a separate jug, dissolve 1/2 teaspoon of calcium hydroxide at a time and add to jar, testing pH each time and keeping note of how much is added. Repeat until test paper indicates pH 9 if dyeing wool/silk or pH 11 for linen/cotton.
- Dissolve twice as much fructose as calcium hydroxide in boiling water and add to jar. Stir with long-handled spoon, gently, creating a vortex.
- Place jar somewhere warm and leave to reduce for a few hours then stir again and leave overnight.
- Vat should be divided into coloured layers by morning with a section of golden dye liquor in the middle and a dark blue foamy ‘flower’ on top. It is ready to dye!
- Very gently lower an upturned egg cup or small glass into the vat, without introducing air, to protect fibres from sediment at the bottom.
Sky-Dye a T shirt using an indigo vat
- Pray or give thanks to the spirit of indigo.
- Scour T-shirt by hot washing in eco-detergent without conditioner.
- Allow to dry.
- Scrunch T-shirt into a loose ball making sure sections of front and back remain on surface.
- Tie loosely with elastic bands or string.
- Wet T-shirt and wring out excess water.
- Wear apron and gloves.
- Move ‘flower’ from surface of vat.
- Gently lower bundled T-shirt into vat and massage the fabric under the surface without introducing air. If it floats, weigh bundle down with a glass.
- Leave in vat for 30 minutes.
- Gently squeeze T-shirt under the surface, swiftly remove from the vat and rinse.
- Allow blue colour to develop for 15 minutes.
- Repeat dip until desired depth of blue is achieved.
TOUBLESHOOTING/FAQS
After 12 hours, my vat hasn’t separated into coloured layers or got a foamy flower on the surface. What’s wrong?
If you ground the pigment thoroughly in a pestle and mortar following all the instructions and there’s no sign of reduction, check the pH again. If it’s altered and now below what you require (9-11), add a little more calcium hydroxide, stir vigorously (without splashing or introducing too much oxygen) and leave in a warm environment for a few hours. In the U.K. climate, we’d recommend using a heated plant propagation mat wrapped around the jar so the liquor is kept warm.
If after rebalancing the pH, the vat still doesn’t show classic signs of reduction as shown in video (e.g. foamy blue flower on surface with coppery film, golden liquor beneath the surface and a layer of sediment at the bottom), dissolve more fructose in boiling water, add to the vat, stir thoroughly again and leave overnight. Offer prayers and libations, speak kindly to the spirit of indigo (as many world cultures do) because it is an initiation that requires respect, patience and determination. With the correct pH, warmth and reducing agent, indigo will reward you with beautiful blues!
In the morning, dip a piece of scoured cloth into the vat, leave for 30 minutes and if you’ve produced blue, it’s ready! Well done! This is not a beginners dye and you just passed indigo’s test!
Why aren’t you using the 1:2:3 recipe?
The popular 1:2:3 recipe works well with indigo pigment that’s had the calcium neutralised. Our pigment is homegrown and as alkali is required to extract it from the leaves, you don’t need to add as much when vatting. Our recipe invites an intuitive approach whereby you’ll learn to read the indicators of reduction for yourself, adjusting your own recipe to suit your tap water pH. You’ve been given more calcium hydroxide and fructose than required to reduce a vat so that you have enough to rebalance and maintain it after usage.
How do I keep this vat going?
Using an indigo reduction vat naturally introduces oxygen that brings it out of reduction and over time, the liquor can become more acidic. If you feel you haven’t done enough dyeing to exhaust the quantity of pigment contained, you can rebalance the vat using a similar process as you started with. Check the pH and bring back to the required level and ‘feed’ the vat after usage with some fructose dissolved in hot water. Stir thoroughly, incorporating all the sediment (so temporarily removing the egg cup/glass) and leave to settle again with a heat source, for a few hours or ideally, overnight.
What if I want to dye a bigger piece of cloth that won’t fit in a mason jar?
You can *carefully* decant your ‘mother’ stock solution into a container just big enough to allow your cloth to move freely but not so big as to dilute the colour too much. This may require trial and error! Woad is a weaker strength pigment than Asian varieties, so we advise using this kit in a small jar and embracing the unique aesthetic of this approach. Decanting may require further rebalancing as described above.
How do I get a deeper blues?
Depth of colour can be achieved with repeated dips that build layers of colour. This reduces the risks of ‘crocking’ (pigment rubbing off.) It’s ideal to leave your fibres in the vat for 30 minutes, then remove and aerate for 30 mins before re-dipping.
How do I dispose of this vat?
Once pigment is exhausted, neutralise alkalinity with some white vinegar and water and you can then safely pour it down a drain.
How can I support the work you’re doing?
Thank you! Please share your beautiful results using this heritage blue by tagging @homegrowncolour and using the hashtags #BritishIndigoFromOrganicWoad #BIFOW #HomegrownColour #BritishIndigo
This will help us find your work and celebrate with you online. We really appreciate your support!