NATURAL DYEING WITH ONION SKINS

NATURAL DYEING WITH BROWN ONION SKINS

At this time of year, while I’m waiting for spring to bring forth fresh nettles and a carpet of dandelions for my natural dyeing, I turn to the kitchen for inspiration.  My first choice is definitely brown onion skins which I save up over the weeks - or rummage for in the bottom of an unguarded box.

Onion skins are rich in tannins and classed as a ‘direct’ (or substantive) natural dye, meaning they can be used without a ‘mordant’ - see Basic Terminology at the end of this blog for more information.  This, and the fact that they are available all year round for free, makes them an ideal source of colour for anyone wanting to have a go at natural dyeing for the first time. 

It's a slow process that can't be rushed and the unhurried element, combined with the uplift of working with colour, adds to the pleasure and the joy.  This project will take about a week from start to finish, but the actual hands-on time is very little.

You need to use 100% natural fibre when dyeing with natural plant dyes, and for this project I’m using an old cotton pillowcase to make ribbons, which could be used for wrapping gifts, tying bunches of herbs and flowers, or incorporating into any other project such as weaving or wreath-making.  Other fibres such as 100% natural wool could also be used.

Start by cutting the pillowcase in half length-ways.  I’m only using half the pillowcase for this 5litre pot.  Then cut off any seams.

It’s important to weigh the fibre while it’s still dry so you will know how much dyestuff to use.

Place the fibre in a pot of cold water and leave it overnight to ‘wet out’.  This expands the fibres and makes them more receptive to the dye.

Whatever fibre you use, it needs to be free of any surface or inherent impurities that will hinder the uptake of the dye, so it needs to be thoroughly ‘scoured’.  This term sounds rather drastic but really just means ‘cleaned’.

Place the fibre into some fresh cold water with a little detergent, making sure there is enough room for the fibre move around freely.  Heat to a gentle simmer (80-90℃ but definitely not boiling!) and hold at that heat for about an hour.  Then remove from the heat and leave the fibre to cool and steep overnight in the pot.

* if using a delicate fibre such as wool, only heat to about 60℃ before removing the pot from the heat and leaving overnight.  Wool will matt very easily so handle carefully and try not to agitate it too much.

Rinse the fibre well in fresh water and hang to dry.  Meanwhile ……

For a bold result with onion skins you need about twice as much weight of onion skins as fibre – so 200%.   As the fibre weighed 36g I used 72g of dyestuff – that’s a lot of onion skins!

Pour in enough kettle-hot water to cover the dyestuff well.  The skins will sink as they soften making space for the water.  Leave to steep overnight to soften the skins and kick-start the release of dye.  Meanwhile …..

Once the fibre is dry, cut or tear it into ribbons – whatever width you prefer.  Tearing rather than cutting gives a softer, gently frayed edge.  Trim off loose strands and pin the lengths together at one end to stop them becoming too entangled in the dye pot.  I ended up with 8 ribbons x 140cm long.

The advantage of dividing the fabric into ribbons before dyeing is that they will move freely in the dye bath and result in more even dyeing results.  Large pieces of fabric will fold over in the dye bath, and need to be constantly lifted in and out to avoid permanent crease lines, which is more difficult to manage.

Soak the ribbons overnight in preparation for dyeing.

Keeping the onions skins in the water they’ve been steeping in,  heat the pot to a gentle simmer; 80 - 90℃.  Keep an eye on the dye bath and lower the heat as soon as the first vey small bubbles begin to rise to the surface.

Don’t allow your dye bath to boil.  This will damage the colour.

Keeping a lid on the pot and working in a well-ventilated space, hold at a gentle simmer for 45 – 60 minutes, and then allow to cool.

Once the dye bath has cooled strain the contents through a muslin-lined sieve, over a bowl, squeezing out as much of the dye from the onion skins as possible.  Then rinse the dye pot well before returning the strained dye.  This is now your dye bath.  The onion skins can be composted.

Add the wetted-out ribbons to the dye bath.  Make sure there is enough solution for the ribbons to move freely.  If there isn’t then add a little more water.  This will not dilute your dye bath as it is the number of dye particles in the dye pot that dictate the colour, rather than the amount of water.

Move the fibre around to make sure that all surfaces are equally exposed to the dye, then heat the dye bath once again to a gentle simmer and hold the heat for 45 – 60 minutes.  Keep moving the fibres around from time to time to ensure an even dye result.

Remove the ribbons from the dye bath and hang them overnight without rinsing, to allow the fibre time to absorb as much of the dye as possible.

Wash the ribbons gently in cold or tepid water with a little detergent.  Onion skins are a relatively lightfast natural dye, but not the most washfast.

Then rinse the ribbons in cold water until the water runs clear – or almost.  Hang them to finally dry, and trim off any excess frayed strands. 

You may or may not want to iron the ribbons, as I’ve done here.  Two of the ribbons are a slightly darker shade than the rest because I mordanted these pieces of fibre before dyeing.  It’s not necessary to do this with a ‘substantive’ natural dye, but the colour will be bolder and more colourfast if you do.

Most natural dyes are indirect (or adjective), and do require mordanting.  This is not a difficult process once you know how.  A step-by-step guide on how to mordant plant fibres for natural dyeing can be found under BLOGS on the elkatextiles.co.uk website, so next time give it a go!

BASIC TERMINOLOGY

·        Colourfast – this refers to the degree to which a natural dye will hold its colour over time after dyeing.  Natural dyes are referred to either as ‘fast’, meaning they will hold their colour relatively well when subjected to washing and natural light, or ‘fugitive’ which means they are inclined to fade rather quickly.

·        Direct and Indirect – natural dyes are either ‘direct’ (also known as substantive) which means they can be used without mordanting, or ‘indirect’ (also known as adjective) which means the fibre must be mordanted before dyeing to achieve satisfactory results.

·        Mordanting – there is no natural affinity between fibres and most natural dyes.  A mordant is a chemical (such as alum, which is a mineral salt) that attaches well to fibre and creates a bond between the fibre and the dye.  The dye then adheres to the mordant.

·        Modifying – once fibre has been dyed, the colour can be ‘modified’ by treating it again with a modifier, such as iron, that will alter the colour.

·        Non-reactive – stainless steel dyeing pots are ‘non-reactive’, meaning the metal will not affect the colour of the dye bath.  Aluminium and copper pots can be used, but will affect the colour of some natural dyes.

·        Scouring – this basically means washing well to make sure the fibre to be dyed is free of anything that will prevent the even uptake of dye, such as oils and natural impurities in the fibre.

·        Simmer – the boiling point of water is 100℃ and a simmer is just below this.  At 80 - 90℃ small bubbles will begin to rise to the surface indicating that the water has reached simmering point.

·        Tannin – this is a natural compound found in plants that will bind to plant fibres and act as a mordant.  It can also be used as a dye.

·        Wetting-out – this is a prolonged soak that will open up the fibres and make them more receptive to the dyeing processes.