Dye Definitions — definitions of dyes, pigments and dyeing terms from Apparel Search
In biology, pigment is any material resulting in color in plant or animal cells as a result of selective absorption, and nearly all types of cells — skin, eyes, fur and hair — contain pigment. In the coloring of paint, ink, plastic, fabric and other material, a pigment is a dry colorant, usually an insoluble powder; there are both natural and synthetic pigments, both organic and inorganic. Pigments work by selectively absorbing some parts of the visible spectrum whilst reflecting others.
Because pigment color is the result of selective absorption, there is no such thing as white pigment. A white object is simply a diffuse reflecting object which does not contain any pigment.
In the coloring of paint, ink, plastic, fabric and other material, a pigment is a dry colorant, usually an insoluble powder. There are both natural and synthetic pigments, both organic and inorganic ones. Pigments work by selectively absorbing some parts of the visible spectrum whilst reflecting others.
A distinction is usually made between a pigment, which is insoluble, and a dye, which is either a liquid, or is soluble. There is no well-defined dividing line between pigments and dyes, however, and some coloring agents are used as both pigments and dyes. In some cases, a pigment will be made by precipitating a soluble dye with a metallic salt. The resulting pigment is called a "lake".
List of pigments
Chlorophyll
Bilirubin
Hemocyanin
Hemoglobin
Myoglobin
Alpha and Beta Carotene
Cyanins
Lycopene
Rhodopsin
Xanthophylls
Canthaxanthin
Zeaxanthin
Chlorophyll
Phycobilin
Hematochrome
Melanin
Pthalocyanine blue
Urea
Alizarin
Bone black
Cadmium pigments
Carbon black
Cerulean blue
Chromium pigments
Cobalt pigments
Crimson
Fugitive pigments
Indigo dye
Ivory black
Lead pigments
Mars black
Naples yellow
Phthalocyanine pigments
Prussian blue
Quinacridone pigments
Red ochre
Sanguine
Sienna
Titanium dioxide
Ultramarine
Venetian Red
Yellow ochre
Zinc white
| The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia (https://en.wikipedia.org/wiki/pigment). Article modified by Apparel Search 11/07/04 |
|
|
On textiles, pigment is the colorant of printing rather than dyeing. A pigment paste — insoluble color, a resin binder and thickener — is printed onto the fabric surface and cured with heat, and the binder film holds the color in place. Most printed T-shirts are pigment prints. The process works on any fiber and any blend, needs no washing-off afterward, and gives exact placement of multi-color designs, which dyeing cannot do. The trade-offs are the mirror image of dyeing's strengths: the color sits on the surface, so hand is stiffer, heavy deposits can crack, and rubbing fastness depends entirely on the binder. Garment dyers and pigment printers can work on the same shirt, but the specification must name which one it wants.
Inorganic pigments — metal oxides and mineral colors such as iron oxide reds and yellows, and titanium dioxide white — are the older family, exceptionally lightfast and heat-stable, with a generally earthy range. Organic pigments are carbon-based, mostly synthetic, and supply the bright, clean reds, blues and greens of modern inks and plastics. Biology runs on its own set: melanin browns and blacks in skin and hair, carotenoid yellows and oranges, and heme red in blood — all working, as the definition states, by selective absorption, and all distinct from the structural blues and iridescence that physical microstructure produces in feathers and wings.
A pigment is insoluble — a dry powder that must be dispersed in a binder to color a material — while a dye dissolves and bonds with the material it colors. A distinction is usually made between a pigment, which is insoluble, and a dye, which is either a liquid or dissolved and taken up by the substrate.
Because pigment color is the result of selective absorption, the page notes there is no such thing as a white pigment in that sense: a white object is simply a diffuse reflecting object. In practice, white pigments such as titanium dioxide color by scattering and reflecting nearly all light rather than absorbing it.
Structural color is color produced by selective reflection or iridescence, usually from multilayer structures, rather than by absorption. Pigment color is the same for all viewing angles; structural color changes with angle. Butterfly wings typically contain structural color, although many contain pigment as well.