What is Acid Dyeing?
When talking to non-dyers the term Acid Dyeing can fill people with horror. I am presuming it is because people envisage vats of sulphuric acid or something similar. In fact the “Acid” is either citric acid (the same acid produced in lemons and limes) or vinegar.
Which one do you use?
I prefer to use citric acid for a number of reasons. Firstly is come in a dry powder which is easy to store and secondly it does not smell and I am not keen on either my studio or house smelling of vinegar.
What does it do?
When using acid dyes the “acid” is added to the dye bath to change the PH of the water. This helps with they dyeing process and ensuring the colours is colourfast at the end. It is often referred to as mordanting which is scientifically incorrect. However instead of getting into the weeds, if someone refers to mordanting yarn for acid dyeing they are referring to adding citric acid or vinegar at some point in the process.
When do I add it?
You can add the acid at different stages in the process.
- Pre soaking the yarn in acid which is the method used below. You can either soak enough for the project or, as I have show below presoak the yarn, dry it and re-soak it when you are ready to use it
- Add it to the dye bath before adding the yarn
- Add it to the dye bath after adding the yarn and dye
- Adding it to the dye bath after dyeing either to encourage extra adsorption of dye
Is it safe?
Citric acid is safe but acid dye powders are poisonous. When handling the dye powder you should always wear a mask and gloves. Also any items you use in the process should be dedicated to dyeing and not used for food preparation again.
Where can I buy Citric Acid?
Citric acid can be bought at a supermarket or online. It is used in the production of bath bombs and some food. Remember even if the acid you are using is food grade, acid dye powder is not edible.
What ratio do you use?
I tend to add 1 tablespoon of citric acid per litre of water
Citric Acid PresoakDifficulty: Easy
Recipe for preparing yarn for acid dyeing
100 gms of yarn (either 1 x 100 gms skein or 10 x 10 gms)
2 tablespoons Citric Acid
2 litres Water
Reusable cable ties or waste yarn
Stirring stick/Wooden spoon
- Ensure there are ties all around the skein so it does not become tangled in the process. You can use colourfast scrap yarn or a reusable cable tie. Do not tie too tight otherwise it will act as a resist.
- Fill bucket with cold water.
- Add 1 teaspoon of Citric Acid and stir until dissolved.
- Add yarn and leave to soak for a couple of hours or over night.
- Gently squeeze out excess liquid and use with dye recipe
- If you do not use all the skeins then dry. When you do require them soak in water .