If the cloth is to be finished as plain white goods it is next starched and ironed (calendared), inspected, and put up in bolts for shipment.
Mercerization
If, however, it is desired either to dye or print the cloth with various colors and designs, it still has several treatments to pass through. White goods are sometimes mercerized, but more commonly this process is employed with cloth that is to be dyed. Mercerization is the treating of cotton yarn or cloth to the action of caustic soda dissolved in water, the remaining soda being removed by a wash of dilute sulphuric acid. The result is an increased strength of fibre, loss of elasticity, silky appearance, and an affinity for certain dyes and mordants.
Napping
Dyeing
The subject of dyeing is one of intense interest and wide scope, but it is unfortunately beyond the field of this brief survey. Suffice it to say that various chemical processes and mechanical devices are employed to give a permanent color to the cloth. (Yarn and raw stock dyeing are less commonly employed in the cotton than in the woolen and worsted industries.)
Resist and Discharge Printing
Some cotton cloth is simply dyed with a solid color and finished, but frequently it is first dyed with one color and then printed with others, or with a chemical which will discharge the dye and leave white figures wherever it touches the cloth. In contrast to this discharge method, where it is desired to obtain white figures on a colored back-ground, it is also possible first to print the figures with a chemical that will resist the subsequent action of the dye-stuff. Where a white ground is used and it is not essential that the colors and design appear on both sides of the cloth it is not necessary to dye at all.
