There are so many different types of paint that choosing one can be confusing unless you know a few definitions and a little about what’s in paint. All paints contain both a pigment and a vehicle. The pigment consists of coloring agents like white lead, titanium, or zinc. The vehicle is the liquid part of the paint that carries the color and can be either water or oil Paint with a water vehicle is called latex paint, and paint with the pigment dissolved in oil is called oil-base. Alkyd paint is a recent hybrid. Its vehicle is composed of both oil and water, which are made to mix by the addition of emulsifiers. Brushes used with latex paint can be cleaned in water; those used with oil-base paint must be cleaned in turpentine or thinners.

The main ingredient of paint is resin. Resins form the hard film that protects a surface. Resins can be either natural or synthetic. Shellac contains a natural resin secreted by insects; when that resin is mixed with alcohol, shellac is formed. The synthetic resins are acrylic, phenolic, silicone, urethane, vinyl acetate, alkyd, and epoxy. The resin is part of the vehicle, and each paint must have at least one resin.

Latex paint is an emulsion; oil-base paint is a solution. If you remember your high school chemistry, an emulsion is a suspension of particles in a liquid, like silt in river water. A solution like salt water undergoes no settling. Latex paint is a suspension of oily globules of pigment and resin in water. When the water evaporates, the globules form a hard skin. Oil-base paint dries by the evaporation of the solvent (turpentine or thinners) in the vehicle; a hard, glossy film is left behind.