Textile Sizing  is the most important textile application for CMC. Its good water solubility, excellent film-forming characteristics and stable solution viscosity make it an efficient sizing agent. Furthermore, modern jet looms have made yarn strength even more crucial and this has contributed to continuous use of Textile Sizing Grade CMC in textile sizing. Normally medium to low viscosity grades are used, depending on the dimensions of the yarn.

In sizing synthetic yarn blends (polyester and cotton), Textile Sizing Grade CMC is often used in combination with a synthetic sizing agent such as polyvinyl alcohol (PVOH) to provide the desired degree of added size film adhesion.

Yarn dimension is of great importance when selecting the most suitable CMC grade for use in sizing. As a rule of thumb: a lower viscosity CMC grade should be used for smaller yarn dimensions.