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A dye is a colored substance that chemically bonds to the material to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber. [2]
Lightfastness is a property of a colourant such as dye or pigment that describes its resistance to fading when exposed to light. [1] [2] [3] Dyes and pigments are used for example for dyeing of fabrics, plastics or other materials and manufacturing paints or printing inks.
This is a list of dyes with Colour Index International generic names and numbers and CAS Registry numbers. This list is incomplete; you can help by adding missing items.
Pigments for sale at a market stall in Goa, India. A pigment is a powder used to add color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use.
Broadly, dyes are soluble and become fixed to a substrate via impregnation, while pigments are insoluble and require a binding agent to adhere to a substrate. Dyes, therefore, must have an affinity for the substance they are intended to color. [4] Chemically speaking, pigments can be organic or inorganic, while dyes are only organic.
Direct dyes, a class of dyes largely for dyeing cotton, are water-soluble and can be applied directly to the fiber from an aqueous solution. Most other classes of synthetic dye, other than vat and surface dyes, are also applied in this way. The term may also be applied to dyeing without the use of mordants to fix the dye once it is applied.
Mordant red 19 is a typical mordant dye. Like many mordant dyes, it features the azo group (RN=NR) and various sites for chelating to metal cations. A French Indienne, a printed or painted textile in the manner of Indian productions, which used mordants to fix the dyes. A mordant or dye fixative is a substance used to set (i.e., bind) dyes on
aal Aal or Indian mulberry (Morinda tinctoria) is the source of the morindone dye sold under the trade name "Suranji". It is extensively cultivated in India for the dyeing of cotton, silk and wool in shades of red, chocolate or purple, dependent on the mordant used.