We enjoyed a natural dyeing day during our Travelling Yarns Retreat in October this year when we were joined by Lauren Macdonald of Working Cloth. You can find out more about her in our interview. We worked with several colours over the day, one dye vat used avocados. This method can be used for dye natural wools or any other protein fibres. Our thanks to Lauren Macdonald for sharing her method and recipe so you can dye your own!
As wools are protein fibers they need to be prepared for the dye bath. Preparation processes include scouring and mordanting which are explained below.
SCOURING
To scour, fill a bowl with warm water (between 50 + 6C) and add some eco washing up liquid (Wool is really PH sensitive - Alkalis really damage it, so if possible use a PH neutral soap), and leave the wool to soak for at least two hours. Gently rinse the fibres. Make sure to be super gentle when doing this as heat and agitation can cause the wool to felt.
MORDANTING
Mordants are usually metallic salts that help bond the dyestuff to the fibre.
Alum – Potassium Alum Sulphate
is the mordant most commonly used by natural dyers for cellulosic (plant) and protein (animal) fibres. It improves the wash fastness and depth of the colour.
Cream of Tartar – Potassium bitartrate
Cream of tartar is a salt of tartaric acid. It is used in addition to the dyebath to brighten and change the colour of some dyes, and to soften wool. Use at 5-6% WOF (weight of fibre).
Iron
Iron will increase the fastness of colour, but it will also ‘sadden’ most colours – darkening them and changing their tone. If used in the mordant process colour changes are more significant than if added to the dye bath. Use at 2-4% WOF, more than this can damage the fibre.
HOW TO MORDANT PROTEIN FIBRES
Weigh the fibre dry, then scour.
Measure alum at 15% WOF and cream of tartar at 6% WOF (optional, as above).
Dissolve both the alum and the cream of tartar in very hot water in a non-reactive container (stainless steel or glass works well for this).
Add the alum solution to the dye kettle with enough warm water (about 45º C or 110º F) to cover the fibre when it is added - usually a 30:1 ration of water to fibre. Stir well.
Add the scoured, wet fibre. Over 30-45 minutes bring the temperature up to 90º C (195ºF) Just under simmer for wool and 85ºC (185ºF) for silk. Gently simmer for an hour, regularly turning the fibre.
Let cool in the bath for 20 minutes.
Remove the fibre from the mordant bath. Allow to hang evenly over a non-reactive rod (stainless steel, plastic) until it stops dripping. Rotate the yarn or fabric frequently so the alum is evenly distributed.
Store the yarn or cloth in a damp white cloth for 24-48 hours. Keep it damp during this period. Once completely dry yarns and fabrics may be stored indefinitely.
PREPARING THE VAT
WHAT YOU NEED
A big stainless-steel pot. Using aluminium or copper will change the colour of the dye bath.
Your dyestuff
Mordanted fabric or fibres that you are using
A wooden spoon for stirring
Gloves
A heat source
Soak your fibres before adding to the pot. Wet fibres will take the dye more evenly and result in a more uniform colour. Ensure that you have plenty of room in your dye bath for your fibre
DYEING WITH AVOCADOS
Avocado pits release a surprising soft pink dye. Wash the green flesh off of the skins and stones – this will ensure the dye is as bright as possible. You can freeze the skins and stones for later use, though I find the fresh plants generally give the brightest colour. The colour will vary by season, water PH, avocado ripeness and variety.
Simmer the stones gently, don’t ‘cook’ them – as this will cause the dye to go brown.
Fill a large stainless-steel pot two thirds full with water.
Add 10 avocado pits, the more pits you use, the deeper the colour will be. Bring the water to a low boil, then reduce to a simmer.
Simmer for about 1 hour. Check the dye regularly to ensure you get the colour you’d like.
Keep the dye overnight and the colour will shift – this might be something you’d like to experiment with.
Put in your fibre in the dye bath and heat gently for about an hour. You can leave the fibres in to steep for longer if you desire a deeper colour.
You can find out more about Lauren and her projects on her website Working Cloth or follow her on Instagram.