HOW TO SCOUR CELLULOSE FIBRE (COTTON AND LINEN)
Before attempting to dye cotton or other plant fibres it is crucial to thoroughly scour your material. Scouring removes all the dust and grease from the fibre.
First wash your material on a hot cycle in the washing machine. Use a non-bleach washing powder and do not use a fabric conditioner.
Half fill a 12 litre stainless steel bucket with water; slowly and carefully add 35g of soda ash to the water (never water to the soda ash). Soda ash causes the water to bubble up vigorously and can be hazardous.
Immerse the washed, wet material to the bucket and stir gently using a long handled spoon. Raise the temperature to boiling point, half cover the bucket and simmer for 2 hours – stirring gently from time to time to ensure that the material is being evenly scoured. After 2 hours remove the bucket from the heat source and allow to cool down enough to be able to remove the material from the bucket.
Rinse thoroughly. If the scouring water is very dirty – repeat the scouring process.
When your material is scoured you are now ready to mordant it.