Aug 7, 2013

How to dye wool using plant material and alum.

 Our garden produced a good crop of purple passionfruit last autumn, and I made a lovely batch of sauce again.
Since I had had a wee experiment last year with dyeing a little wool with some of the passionfruit skins, I thought I'd do it properly this year. See if I could get that soft pink again. Since pinks and purples are some of the most difficult colours to get from plants.

So here a "basic recipe"which you can use for different plant experiments.
Try it with onion skins, parsley, poplar tree twigs and leaves, dahlia flowers (when flowering is done), coreopsis, marigolds, iris leaves, geraniums, carrot tops, cinerarias, purple prunus leaves, fennel, yellow oxalis flowers, etc. try roots, or leaves, fallen bark or twigs. You will start looking at plants in a different light altogether. (just make sure it is not a protected species)

Needed: *weighing scales,
*pots and pans (to be used for dyeing only), preferably stainless steel,
*measuring spoon and stirring spoon (for dyeing only),
*spare mixing container
*plastic or muslin mesh bag to cook plant material in,
*cream of tartar (potassium bi-tartrate, also used in baking and preserving.),
* alum ( potassium aluminium sulphate, from your chemist.)
*about 100 grams of clean wool, or silk, mohair, alpacca (protein fibres)
* as much plant dye material as you can find, I used 2 cups of cut up passionfruit skins here.

A popular book on the NZ fibre-artisans' shelf.
I have used this book a lot when natural dyeing, it has recipes in it for native plants and those you can actually find in your NZ neighbourhoods' gardens.
Alum is the most common mordant used and nearly always used in conjunction with cream of tartar, usually 3 or 4 parts alum to 1 part cream of tartar. A mordant chemically opens up the fibres to accept the dye molecules.
There are some plant dyes that don't need a mordant, like walnut husks or silverdollar gum , but mostly you want to be sure you don't pour the dye down the sink without first being absorbed by the fibres, right?

*Step 1*  I chopped up the empty passionfruit skins, some of which were quite dry and wrinkly. Any moldy ones were thrown out. I put them in a dyeing saucepan and covered with water, then simmered softly for half an hour.

 *Step 2* Wet the wool gently and thoroughly.
Using a 5ml measuring spoon, mix 4 spoons of alum and 1 spoon of cream of tartar (this is for 100 grams of wool) with some hot water and dissolve. Tip the mixture into the pot with enough water to cover the wool. Place the wet wool in the alum bath.
Simmer softly for three quarters to an hour.
Do not stir the wool, it will felt horribly. You can gently move it once or twice with the spoon.

Cool the wool. Strain it into a colander. 
You now have mordanted wool. You can store this in the dark up to 3 days for peak performance, or use straight away. If you are impatient like me, it would be used in the next 5 minutes!

 *Step 3* Strain the plant material from the dye liquid, but throw nothing away.
Put the plant material in a mesh bag to stop it from getting entangled in the wool. Tie up with a rubber band or string, but not metal. Iron, copper or even aluminium can alter the results of the colour.

*Step 4* Put the mordanted wool into the dye liquid, making sure it is covered. Otherwise add some water. This does not "dilute "the dye; there are still just as many dye molecules floating about in the liquid as before.
Put the mesh bag with plant material back in also.
Bring to a soft simmer and let it do this for half an hour to 3/4 hour. Do NOT stir, but you can gently and slowly turn the wool over a couple of times. Or not if you want to be on the safe side of non-felting.

*Step 5*  Cool and strain the wool. Any vegetable matter in the wool can be picked out after drying or during spinning.
Rinse very gently in the sink with same temperature as the wool (remember heat and friction cause felting), with an optional dash of white vinegar .

*Step 6*  Dry outside in a soft breeze if you get one. 
You shouldn't use pegs as they leave squeeze marks. According to my book, most bad fading occurs quickly but the gentle softening of colour can take longer. 

So far so good with my passionfruit-skin dyed wool!
But I wanted more of the pinkish-ness, although it was a good flesh colour.

I had picked another dozen ripe passionfruit that morning, so a new experiment this time!
Solar dyeing in preserving jars this time!
This involves no cooking. But you need nice weather for some days.
I scooped out the yummy pulp and put it in the fridge for later yoghurt toppings.
The skins were cut into pieces and divided into 3 mesh bags.
Another alum mixture was made; 4 x 5ml. alum with 1 x 5ml. cream of tartar, dissolved in water.
I divided this mordant water over 3 preserving jars.
Then added wet fibre ( wool, alpacca, silk sliver) to the jars so that they were in there loosely, not packed.
 I added the bags of passionfruit skins, making sure everything was covered by the fluid.
Then sealed the jars with lids and cling-wrap and rubber-bands.
And put them in the sun for 5 days! I shook them so now and then and turned them around.
Well, I intended to do 5 days, but I forgot and it turned into a week...

The wool (middle) took the dye the best, although in places more pale peachy with hints of green tinges. The silk was not white anymore, but nothing spectacular unfortunately. The alpacca (left)  was somewhat paler than the wool.

Not a bad set of scientific experiments , don't you think? for a girl who failed her chemistry miserably at high school!


Unknown said...

Thank you for your tutorial it was wonderful and I learned a great deal will look out for the book you spoke of.

Are you able to give me the name of the Chemist you get your potassium aluminium sulphate from please?

Can you store the dyes in jars if you don't add the mordant to it? If so for how long can I store them?

Regards Chris

Elmtree said...

hi Chris, the book is a NZ classic amongst Creative Fibre Spinners and Weavers. Your library or local club is bound to have a copy.
Cannot remember the name of the chemist, it was years ago I purchased the alum, but it is not a horrid poison. They asked why I needed it, I explained and they sold me some by weight.
You can store the dye for a little while, but it is in danger of either getting moody, or losing its potency. But you could experiment with freezing?

Elmtree said...

Sorry, it gets mouldy not moody. Autocorrect is playing teacher when I could spell quite nicely, thank you computer... lol.