Before any fabric is dyed it must be scoured to remove any trace of wax, chemicals, oil or impurities that might hinder the fabric’s ability to accept the dye
This process involves washing and rinsing the fabric with an alkaline solution, usually a mild solution of soda ash, lye or caustic soda. The fabric is brought to the boil [in this solution] for a short time, sometimes under pressure, depending on whether it is in a domestic or commercial environment.