Pigment

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.

Many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have special properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors. It must be stable in solid form at ambient temperatures.

For industrial applications, as well as in the arts, permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken.

Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food, and other materials. Most pigments used in manufacturing and the visual arts are dry colorants, usually ground into a fine powder. This powder is added to a binder (or vehicle), a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.

Biological pigment

Biological pigments, also known simply as pigments or biochromes are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores.

Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well.

Biological pigments

See Conjugated Systems for electron bond chemistry that causes these molecules to have pigment

Pigment (software)

Pigment is a 3D scene graph (or canvas?) library designed to easily create rich application user interfaces. Pigment uses OpenGL for rendering, and supports OpenGL 1.2 to 2.1 and OpenGL ES-CM 1.1 plugins. Embedding of images and video utilizes GdkPixbuf and GStreamer, with fast video playback via hardware scaling and colour space conversion. Other features include asynchronous image loading, thread-safety, GTK+ integration via a custom widget, and fully supported Python bindings.

Pigment is known to work on Linux (x86, PowerPC and ARM), Solaris (x86 and SPARC), OS X, and Microsoft Windows. Pigment is free software, licensed under the GNU Lesser General Public License.

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