Indigo dyed cloth - unscoured on the left, scoured on the right.

Indigo dyed cloth - unscoured on the left, scoured on the right.

Yarns and fabrics need to be scoured before dyeing. Soured items dye more evenly, the dye penetrates better, and dyed colours are more lightfast and washfast.

Note: Fabrics sold as “ready for dyeing” may not need scouring.

Supplies:

Soda ash & Synthrapol (for cotton)
Orvus paste soap (for silk & wool)

Scouring cellulose fibres:

Cotton, linen, hemp, etc.

  1. Fill a large pot so that cloth or yarns are covered and not crowded.

  2. For each 450g (1 pound) of goods add 10ml (2 teaspoons) Synthrapol and 20g (4 teaspoons) soda ash. 

  3. Simmer for approximately 1 hour. Cotton is full of wax, pectic substances, and oil, all of which must be removed. The resulting wash water may be yellow brown. Bleached white cotton yarns and fabrics may not need as long.

  4. Allow fibre to cool down slowly and then rinse in warm water.
               
    Fabrics marked PFD (Prepared for Dyeing) may only need a light scour or none at all (always test before omitting). To lightly scour fabrics (not yarns) you may use a top-loading washing machine. Use the above recipe and hot water.

Scouring Protein Fibres:

Silk, wool, hair etc.

  1. Fill a large pot so that cloth or yarns are covered and not crowded.

  2. For each 450g (1 pound) of goods add 5 ml (1 teaspoon) orvus paste soap.

  3. Heat gently to 60º C (140º F) for approximately 1 hour. Turn gently but do not agitate

  4. Allow fibre to cool down slowly and then rinse in warm water. 
               
    Fabrics marked PFD (Prepared for Dyeing) may only need a light scour or none at all (always test before omitting). To lightly scour fabrics (not yarns) you may use a top-loading washing machine. Use the above recipe and warm water. To avoid felting do not agitate.

See our free lesson on Scouring at Maiwa School of Textiles