The warp yarn is coated by a ‘size’ before the weaving step to protect it from the abrasion and prevent the yarn from breakage and damage. The presence of size on the fabric makes it stiff and complicates the dyeing and finishing processes. Therefore, the fabric needs to be desized, meaning that the ‘size’ coating is removed.
Scouring is conducted simultaneously in order to remove foreign matters and impurities adhering to the fibres.