Basic Paint Components and Their Role in Quality, Performance
Part 2 of a 3-part article on the factors that influence a paint’s quality and how well it will work in a particular space
This article was originally published in 2015 and has been updated to reflect current information.
To select the most appropriate paint or coating for the space, it helps to understand what goes into the product. Most paints consist of the same basic components: pigments, binders, liquids and additives. Each component serves a role in determining the quality of the paint as well as its performance both during and after application.Pigments, either organic or inorganic, are what give the paint its color and its ability to cover. The level of concentration of pigment in a particular paint also has a direct impact on the durability of the paint’s film. One measure of a paint’s quality is the pigment volume concentrate (PVC). PVC, expressed as a percentage, is the ratio of the pigment volume to the total volume of solids in a particular paint. A PVC value of 45 is generally considered to be the optimum level of concentration for most applications. Lower values typically produce a higher gloss finish but have lower color uniformity, lower tensile strength, and lower water permeability. A higher PVC increases the water permeability and with it, an increased risk of blistering and corrosion.
A paint’s PVC rating impacts performance in other ways. Lower PVC paints tend to adhere better, but higher PVC paints are more durable and are easier to clean.
Paint binders are used to firmly attach the pigment to the surface and into a continuous film. The type and quantity of binder used in the paint impacts performance factors, such as durability, stain resistance, adhesion, and resistance to cracking. In general, the higher the ratio of binder to pigment, the higher the quality of the paint. In high-quality paints, manufacturers can change the binder used to vary the paint’s performance characteristics, including its resistance to moisture, ultraviolet rays, and abrasion. Other binders can improve a paint’s flexibility or adhesion. It is important that facility managers work with manufacturer’s representatives to determine which binders are most suitable for a particular application.
The liquids in a paint typically account for somewhere between 25 and 50 percent of the paint’s volume. Their function is to carry the pigments and the binders. There are two different types of liquids used in paint formulas: solvents and dilutents. Solvents hold the binder and pigment in suspension until the paint sets. In oil-based paint, the solvent is an organic material such as a paint thinner. In latex paint, water serves as the solvent. Dilutents also help to keep the pigments and binders in suspension, but they are used primarily to reduce the cost of the paint. High quality paints tend to have lower levels of dilutents.
Manufacturers use additives in a paint to enhance certain qualities. For example, thickeners and modifiers are used to ease application. Defoamers reduce the appearance of bubbles in a paint’s surface. Hardness can be enhanced through the use of co-solvents. Biocides can be added for applications in exterior or high moisture areas to limit biological growth on the paint’s surface.
James Piper, Ph.D., PE, is a writer and consultant who has more than 25 years of experience in facilities management. He is a contributing editor for Building Operating Management.