what is dye

A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This differentiates dyes from pigments, which do not chemically bind to the material they color. Dyes are generally applied in an aqueous solution and may require a mordant to improve their fastness on the fiber. Most dyes used in the modern world are synthetically produced from substances such as petrochemicals, although some are derived from natural sources such as roots, berries, bark, and leaves. Dyes are used to impart color to textiles, paper, leather, and other materials, and their color is dependent upon their ability to absorb light within the visible region of the electromagnetic spectrum