Textile Grade Water-Soluble Polyester Chips for Yarn Sizing It is an entirely water-based polyester resin with high stability and can be 100% dissolved in water without alcohol or other solvents. WSP Resin is mainly used as Sizing Chemicals for Textile. The sizing operation is the link between yarn making, weaving, and finishing in the textile industry. The process of applying protective adhesive coating on the surface of yarns is known as sizing. Sizing chemicals are mainly applied on warp yarns to improve their performance during the weaving process as warp yarns, which are subjected to abrasion with various loom components during weaving.