Tips for choosing paints

Many different ingredients go into making paint and different types of paint have different ingredients. An interior oil-based paint, for example, has a vastly different formulation than exterior latex paint because it’s designed to perform under different conditions. To choose the best paint for a particular job, you should understand how the various paint formulations perform under different conditions. Here are some tips for choosing paints.

Basic ingredients

A typical batch of untinted base paint may contain 20 or more ingredients, but the basics are

• Pigments, which are finely ground particles, give paint the ability to hide the surface to which it’s applied. This is not the same as the colorants that are added at the paint store to produce the color you want.
• Resins, also called binders, are the ingredients that hold the pigments and colorants in place after the paint dries.
• Solvents, sometimes called carriers, are the liquids that carry the pigments and resins, and allow you to transport them from the container to the brush or roller and then to the surface to be painted. In latex paints, the primary solvent is water, while oil-based paint solvent is typically mineral spirits. Both evaporate as the paint dries.
• Additives are not present in every can of paint, but they can be introduced to accomplish everything from increasing workability and leveling characteristics to providing added mildew resistance.

Paint types

Latex (water-based) paints have become increasingly popular, as manufacturers continue to improve performance. Latex paints consist of a PVA resin and water as a solvent. The “latex” in the name refers to its ability to remain flexible when dry, meaning it’s less like to crack and peel over time. Easier use and cleanup are also very valuable to professionals on a time schedule.

Acrylic paints are much like latex, except that the PVA resin is replaced by acrylic resins. These are generally more durable than latex. Most professionals recommend acrylic or at least an acrylic/latex blend for best quality in most applications.

Alkyd (oil-based) paints use a synthetic resin and typically use mineral spirits as the solvent. Oil-based paints must be cleaned with mineral spirits or some type of paint thinner, and they are typically not considered “green” options as they usually have higher VOC (volatile organic compounds) and are flammable while wet. Oil-based paints also tend to yellow and become brittle with age.

Plant-based oil paints may sound like an environmentally friendly choice, but they often contain more VOCs than other choices. The plant-based oils are typically something like linseed oil, which can be harmful or fatal if swallowed.

Milk paints, also called casein paints after the milk protein from which they are derived, are typically bought in powder form. They are then mixed in batches large enough to be used immediately as they can sour if left in a wet state for too long. Designed for interior use only, milk paints are desired for their environmental benefits.

The finish

A paint’s finish refers to how reflective the dried surface will be. In general, the shinier the finish, the easier it will be to clean. Recent improvements in manufacturing, however, have resulted in many flat/matte and low-sheen paints that are as easy to clean as glossier choices. The basic finishes, in order from no-shine to high shine, are flat or matte, eggshell, satin, semi-gloss and gloss.

What paints to use where

Areas that demand the most from paints typically have paints designed especially for them. For example, most companies produce a paint specifically formulated for ceilings. They are typically bright white, latex or acrylic, and are formulated to go on easily with minimal drips or spatters.

Kitchen paints must stand up to a lot of abuse. These high-traffic areas are susceptible to spills and splatter from food preparation, so a latex/acrylic semi-gloss on the walls and latex/acrylic or oil-based gloss for the trim, should work best.

Bathrooms put demands on paint that are similar to kitchens with the added risk of high humidity. For bathrooms, you want a surface that resists water and inhibits mold and mildew growth. Use latex/acrylic semi-gloss for walls and ceilings, and latex/acrylic or oil-based semi-gloss or gloss for trim.

Basements require specially formulated masonry paints that are resistant to water and suitable for porous concrete surfaces. Do not use a regular interior or exterior paint for this job.

Dry climate exteriors are subject to a lot of shrinking and expanding of the substrate due to temperature fluctuations, which means latex/acrylic paints should perform better due to their flexibility. They will shrink and expand with the substrate to prevent cracking and peeling. On the other hand, wet climate exteriors do better with oil-based paints, as latex paints can freeze, shrink and crack in cold, wet conditions.

Is it worth it?

Paints vary widely in price, usually because of what goes into them. Whether they are worth the price for your particular job depends on what you want the paint to do.

For example, the most expensive pigment used in paint is titanium dioxide, which is a white powder with very good hiding properties. Better paints contain a higher percentage of this pigment, so they cost more and hide the underlying surface much better.

The best resins penetrate the pores of a surface better and resist blistering, peeling and wear. Typically, the best resins are 100 percent acrylic, and since resins are the most expensive component in any paint, the best paints are more expensive.

High-quality paint also has more solids, as determined by the ratio of pigments and resins to solvent. Better quality paints have as much as 45 percent to 50 percent solids by volume, while lower quality paints have 30 percent or less.

Additives designed to improve the application and performance qualities of paint can also raise the paint’s price. For example, added thickeners provide a more even, thicker coat of paint, surfactants help the paint soak into the substrate and stabilize the color and viscosity, and mildewcides limit mold and mildew growth for a few years after application.

All this means that for the most part, the more expensive a paint is the better quality it is. And that extra money homeowner are willing to pay for paints is well-spent if it results in a better quality job that looks better and performs longer.