Re-sist′.
（Dyeing.) A material applied to cotton cloth to prevent the action of a mordant or color on those portions to which it is applied in the form of a pattern. Resists act mechanically or chemically. Fat or paste forms a mechanical resist, as it prevents the access of the mordant or color. Chemical resists act upon the color, and prevent its fixing itself in the fabric.
2. (Calico-dyeing.) A process in which those portions of the cloth which are intended to remain uncolored are saturated with a substance which resists the action of the dye when immersed in the dye-vat. The resist, a preparation of copper, imparts a brown tint to those parts to which it is applied, and the cloth is dipped in the dyeing solution, indigo in lime-water, with a proportion of copperas, which deoxidizes and decolorates the indigo; on being removed from the vat the cloth is of a greenish hue, which soon becomes blue by the reoxidation of the indigo on its contact with the air; the parts covered by the resist become charged with blue in the vat, the copper salt parting with its oxygen to the indigo. The blue thus formed has no union with the fiber, and is easily removed by weak acid, while that formed in the spots not touched by the resist remains fast. In the china blue process the figures are printed with indigo thickened with paste, and by alternate immersion in lime-water and solution of copperas the indigo is dissolved and fixed in the spots where so applied by similar chemical reactions. In the discharge process, employed for black and white, or red or chocolate and white, the cloth is passed through red or iron liquor, dried, and dipped in a mordant, — this is termed padding; it is then printed with citric acid, thickened with wasted starch, which discharges the mordant, so that when dyed the discharged figures are left white. Logwood is used for black, and madder for red and chocolate.
