Colour fastness is a term—used in the

dyeing Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular c ...

textile Textile is an Hyponymy and hypernymy, umbrella term that includes various Fiber, fiber-based materials, including fibers, yarns, Staple (textiles)#Filament fiber, filaments, Thread (yarn), threads, different #Fabric, fabric types, etc. At f ...

materials—that characterizes a material's

colour Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...

's resistance to

fading In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is ...

running Running is a method of terrestrial locomotion allowing humans and other animals to move rapidly on foot. Running is a type of gait characterized by an aerial phase in which all feet are above the ground (though there are exceptions). This i ...

. Colour fastness is the property of dyes and it is directly proportional to the binding force between photochromic dye and the fiber. The colour fastness may also be affected by processing techniques and choice of chemicals and axillaries. The term is usually used in the context of

clothes Clothing (also known as clothes, apparel, and attire) are items worn on the human body, body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin sheets of materials ...

. In general, clothing should be tested for colour fastness before using

bleach Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...

or other cleaning products. Light fastness,

wash WASH (or Watsan, WaSH) is an acronym that stands for "water, sanitation and hygiene". It is used widely by non-governmental organizations and aid agencies in developing countries. The purposes of providing access to WASH services include achievi ...

fastness, and rub fastness are the main forms of colour fastness that are standardized. The light fastness of textile dye is categorized from one to eight and the wash fastness from one to five, with a higher the number indicating better fastness.

Dye and the binding forces

dye 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 ...

is a

colored ''Colored'' (or ''coloured'') is a racial descriptor historically used in the United States during the Jim Crow Era to refer to an African American. In many places, it may be considered a slur, though it has taken on a special meaning in Sout ...

substance that chemically bonds to the substrate to which it is being applied. Dyes are classified according to their solubility and chemical properties. Dyes are selected according to the affinity, any given dye does not apply to every type of

fiber Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate ...

. The different binding forces acts between the dye and substrate. Such as

Van der Waals force In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and ...

s include attraction and repulsions between atoms, molecules, and surfaces, as well as other intermolecular forces. Example is

Direct dye A substantive dye or direct dye is a dye that adheres to its substrate, typically a textile, by non-ionic forces. Overview The amount of this attraction is known as "substantivity": the higher the substantivity the greater the attraction of th ...

s application to

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...

that results poor fastness properties to washing. The bond differs from

covalent A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atom ...

bonding in reactive dyes when applied to cotton that may result far better fastness than direct dyes. Covalent bond is a stronger bond, caused by correlations in the fluctuating polarizations of nearby particles (a consequence of quantum dynamics).

Pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

s as an exception do not bind chemically with textile materials.

Importance of colour fastness

Colour is an influential element of fashion and aesthetics of clothing, it has great value for both the user and the brand. Colour is one of the most significant features in attracting customers and inclines to buy a product/garment. Retaining the original colour is one of the important quality parameter of coloured textiles. Colour fastness is rated poor if it does not comply with the tests by exposing to

laundry Laundry refers to the washing of clothing and other textiles, and, more broadly, their drying and ironing as well. Laundry has been part of history since humans began to wear clothes, so the methods by which different cultures have dealt with ...

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 t ...

, rubbing and other agencies such as

perspiration Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distr ...

Test methods for colour fastness

Fading, change in colour, staining to adjacent textiles material were common complaint of poor textile quality materials. Standardized testing for colourfastness and other parameters were established in 20th century by leading industrialized countries such as US,UK, Europe and Japan.

AATCC AATCC—the American Association of Textile Chemists and Colorists— is a 501(c)(6) not-for-profit professional association that provides test method development, quality control materials, educational development, and networking for textile and a ...

International Organization for Standardization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in A ...

and Society of Dyers and Colourists played vital role in establishing the test methods. There are various tests and testing methods according to the physical and functional requirements from the product. For example fastness to saliva may be important for kids-wear and perspiration and light is important for a

golf Golf is a club-and-ball sport in which players use various clubs to hit balls into a series of holes on a course in as few strokes as possible. Golf, unlike most ball games, cannot and does not use a standardized playing area, and coping wi ...

shirt. European and US retailers use ISO and

standards respectively.

References

External links

AATCC Test Methods - Textile Testing Research and Development
* Textiles Properties of textiles {{Color-stub