Pigments are insoluble, fine particle-size materials that confer on a
paint its color and opacity. Pigments are used in paint formulation to
carry out one or more of the following tasks:
1. Provide color
2. Hide substrates and obliterate previous colors
3. Improve the strength of the paint film
4. Improve the adhesion of the paint film
5. Reduce gloss
6. Reduce cost Pigments should be insoluble in the medium in which they are used,
chemically inert, free of soluble salts, and unaffected by normal temperatures.
They should be easily wetted for proper dispersion, nontoxic,
noncorrosive, and have low oil-absorption characteristics. They should
be durable and fast to light (as much as possible).
In general the following properties of pigments are important in selecting
a pigment for any particular product:
a. Hiding power
b. Tinting strength
c. Refractive index
d. Light-fastness
e. Bleeding characteristics
f. Particle size and shape
