Pigments and their classification

Pigment is derived from word “pigmentum” means coloring matter.
“Pigments are organic and inorganic materials which are practically insoluble in medium in which they are incorporated

1. Pigments and their classification
Introduction
Pigment is derived from word “pigmentum” means coloring matter.
“Pigments are organic and inorganic materials which are practically insoluble in medium in
which they are incorporated”
Pigments are used almost 30,000 years ago. The first synthetic pigment was Prussian blue which
was synthesized in 1704. About 2000 BC natural ocher was burnt sometime in mixture with
manganese ore to produce red, violet and black pigments for pottery.
Classification of pigments
Pigments are classified into organic and inorganic pigments.
Organic pigments are based on carbon chains and carbon rings. However, they can also contain
metallic (inorganic) elements that help stabilize the properties of the organic component.

Inorganic pigments, chemical compounds not based on carbon, are usually metallic salts
precipitated from solutions.
Organic Pigments are classifying into following:
 Azo pigments
 Polycyclic pigments
 Anthraquinone pigments
 Dioxazine pigments
 Triayl carbonium pigments
 Quinophthalone pigments
Inorganic pigments are classified into following:
 White pigments
 Black pigments
 Special pigments
 Color pigments

2. Properties of organic pigments
The properties of organic pigments differ from inorganic pigments. The properties of organic
pigments are as follow:
 High color strength
 Give bright shades
 High light fastness
 Good weather fastness
Properties of inorganic pigments
 Weak color strength
 Dull shades
 Low light fastness
 Low weather fastness
Applications of pigments
There are many applications of pigments. Pigments are used for coloring of leather, building
materials, paper, floor covering and ceramic glazes.
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 vehicle (or binder), a relatively neutral or colorless
material that suspends the pigment and gives the paint its adhesion.