Pigments are tiny solid particles that are used to enhance the appearance by
providing color and/or improve the physical (functional) properties of the paint
film. Pigments used to provide color generally range from 0.2 to 0.4 micron in
diameter; functional pigments are typically 2 to 4 microns in diameter, but they
may range as high as 50 microns. The pigments need to be permanently insoluble
in the binder of the coating. If they were to dissolve, they could change the
properties of the binder and lose their capability to provide a particular appearance
enhancement and functional improvement.