sw-art-WhySpecifyingPaint

Color is just one aspect of a designer’s role in helping clients pick paint.

When helping a client choose paint colors for a project, some designers confine themselves to just that ― color. Some fail to consider choosing between an alkyd and a latex, or an enamel and an acrylic.
But choosing a paint that doesn’t perform well for a specific application can lead to costly mistakes, angry clients and a damaged reputation. That’s why it’s important for designers to understand the different features, benefits and limitations of different paints and coatings and to be actively involved in the specifying process. “In addition to helping clients choose the best colors for a space, designers can work with paint contractors to identify and recommend the paint types that will provide the best results for the space as well,” says Jim Alberts, director of marketing, commercial segment, for Sherwin-Williams.

Not all paint is created equal

More than ever in the paint market, quality counts. Paints are becoming more sophisticated and their formulations increasingly specialized. What key things should you look for when specifying paint? It isn’t enough to simply rely on the name of a manufacturer, because most manufacturers offer a range of paint types and qualities. Instead, you should look at the components that make up the paint, particularly its concentrations.
Cost is often the deciding factor when it comes to specifying paints and coatings. Clients don’t always look at the cost of a project based on its life cycle, but rather at the initial price tag. That’s why it’s important for designers to educate clients on the long-term financial and performance benefits of choosing quality paints.
Top-quality paints are more expensive because they contain top-quality ingredients and a larger percentage of solids. More solids result in a thicker, longer-lasting coating. Quality paints are easier to apply, flow better and splatter less during application, require fewer coats for the same coverage, and adhere to surfaces and hide uneven coloration in the substrate better. They also resist chalking, fading, peeling, flaking, dirt and mildews better. And despite costing more per gallon, they are actually more economical since they last longer and cost less per year.

What to look for in paint

Most paint consists of a mix of finely ground solids ― including binders, pigments, and additives such as drying oils and mildewcides ― dissolved or suspended in a liquid carrier. The pigment in paint adds color and determines how well it covers, or hides, the underlying surface. The binder knits the particles of pigment together into a film and binds it to the underlying surface. The carrier evaporates as the paint dries, leaving the solids behind as a thin surface film.
Pigments. Quality paints use premium hiding pigments such as titanium dioxide along with small amounts of other pigments to provide the color. Lesser quality paints use less pigment but extend it with fillers such as talc, clay, calcium carbonate or silica. These fillers will provide good hiding capability initially, but break down pretty quickly over time, particularly when exposed to the elements.
Paint binders. The type, quality and quantity of binder used in a particular paint will affect a wide range of performance characteristics, including adhesion; resistance to moisture permeability, cracking and stains; and damage from abrasion and sunlight. In most cases, the higher the quality of the paint, the higher the paint’s ratio of binder to pigment, or “pigment-volume concentrate.” The pigment-volume concentrate indicates how much binder the paint contains to surround and protect the pigment. A pigment-volume concentrate value of 45 percent is considered to be the optimum level for most applications.
Liquid carrier. Paints fall into two categories when it comes to the liquid carrier: water-based (latex) paints and oil-based paints, also referred to as “alkyds.”

Characteristics of oil-based paints

Top-quality oil-based paints have excellent adhesion characteristics, meaning they get a tight grip on the surface being painted. Good adhesion is essential for a durable paint job. However, oil-based coatings tend to oxidize and get brittle over time, which can lead to cracking in exterior applications, and yellowing and chipping in interior applications. Plus, oil-based paints can take up to 24 hours to dry.
However, there are two circumstances when oil-based coatings are the best choice:
  • When repainting exterior surfaces with heavy “chalking” (chalk is the powdery substance that comes off on your hand when you run it across the surface).
  • When repainting any exterior or interior surface that has four or more layers of old oil-based paint.

Characteristics of water-based paints

Compared to oil-based paints, top-quality latex paints have greater durability, color retention and chalk resistance, so they continue to look good for years. Since they are less brittle and more elastic than oil-based paints, they are also more resistant to cracking. Latex paints also dry much faster than oil-based paint, which allows for a quicker second coat.
Latex paints with 100 percent acrylic binders are especially durable and highly flexible. They tend to adhere extremely well to a variety of surfaces: wood, particularly in areas that experience freezing temperatures; stucco and masonry; and weathered aluminum siding. They’re also highly resistant to mildew and have greater resistance to paint failures such as blistering, flaking and peeling.
Industry experts claim that nearly 95 percent of all interior paint sold today is latex. That’s not surprising considering its faster drying time, lower ratios of volatile organic compounds (VOCs) and easy cleanup compared with those of alkyds.

Sheen

The sheen of a paint is the amount of light reflected by the surface of a paint finish. Picking the right sheen level for a job involves both aesthetic (how it will look) and practical (how it will perform) considerations. For additional information on paint sheen, see the related story in this issue of STIR eExtra.

Where to find information

The best source for information in evaluating paint quality is the manufacturer. Manufacturers can tell you about the different performance characteristics of their paint lines, as well as provide information on the ingredients, including the types of pigments and binders used and the percentage of solids.