Paint Ingredients ~ Liquids

LIQUID – THE LIQUID PORTION OF THE PAINT (ALSO REFERRED TO AS THE "CARRIER") PROVIDES A WAY TO GET THE PIGMENT AND BINDER FROM THE CONTAINER ONTO THE SURFACE THAT IS TO BE PAINTED

• For most oil-based and alkyd paints, the liquid component is paint thinner, which is a combustible solvent made primarily of mineral spirits, a petroleum distillate of aliphatic hydrocarbons.
• For shellac-based primers and varnishes, the liquid is denatured alcohol.
• For clear and pigmented lacquers, the liquid is usually lacquer thinner or another solvent that is "stronger" and more flammable than paint thinner.
• For latex paints, the liquid is primarily water (but see additives section below).

The pigments and the binder are what are left on the surface when the paint dries and the liquid portion evaporates. Together, they are called the solids portion of the paint:

PIGMENTS + BINDER = SOLIDS

The coating (e.g., paint, stain, primer) consists of the solids and the liquid:

SOLIDS + LIQUID = COATING

When a paint is applied at a given thickness, and it then dries, the proportion of solids and liquid determines how thick the dried paint film will be:

Thus, a higher solids content can provide a thicker dry paint film , which results in better hiding and durability . For this reason, it is recommended that paints not be thinned unless necessary (such as for application by spraying), since thinning reduces the solids content of the paint per unit of volume. The solids content of a paint may be in its spec sheet. This can be expressed by weight or volume. The weight solids of a paint is usually higher than its volume solids. Volume solids are a better indicator of performance than are weight solids. Latex paints generally range from 25% to about 40% volume solids, depending on type and quality. Alkyd and oil-based paints can exceed 50% volume solids.

Information provided by The Paint Quality Institute