Dye

Drying colored cloth
Chemical structure of indigo dye, the blue coloration of blue jeans. Although once extracted from plants, indigo dye is now almost exclusively synthesized industrially.[1]

A dye is a colored substance that chemically bonds to the substrate 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]

The majority of natural dyes are derived from non-animal sources such as roots, berries, bark, leaves, wood, fungi and lichens.[3] However, due to large-scale demand and technological improvements, most dyes used in the modern world are synthetically produced from substances such as petrochemicals.[4] Some are extracted from insects and/or minerals.[5]

Synthetic dyes are produced from various chemicals. The great majority of dyes are obtained in this way because of their superior cost, optical properties (color), and resilience (fastness, mordancy).[2] Both dyes and pigments are colored, because they absorb only some wavelengths of visible light. Dyes are usually soluble in some solvent, whereas pigments are insoluble. Some dyes can be rendered insoluble with the addition of salt to produce a lake pigment.

  1. ^ Steingruber, Elmar (2004). "Indigo and Indigo Colorants". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a14_149.pub2. ISBN 3527306730.
  2. ^ a b Booth, Gerald (2000). "Dyes, General Survey". Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH. doi:10.1002/14356007.a09_073. ISBN 3527306730.
  3. ^ Burgess, Rebecca (8 November 2017). Harvesting Color: How to Find Plants and Make Natural Dyes. Artisan Books. ISBN 9781579654252. Retrieved 8 November 2017 – via Google Books.
  4. ^ "dye - Synthetic dyes | Britannica". www.britannica.com. Retrieved 2022-06-20.
  5. ^ Kassinger, Ruth (2003). Dyes : from sea snails to synthetics. Internet Archive. Brookfield, Conn. : Twenty-First Century Books. ISBN 978-0-7613-2112-5.