Sizing

Sizing or size is any one of numerous specific substances that is applied to or incorporated in other material, especially papers and textiles, to act as a protecting filler or glaze.

Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials; it is the term used for oil-based surface preparation for gilding (and is also known as mordant in this context); and it is used by painters and artists to prepare paper and textile surfaces for some art techniques.