Brushing up on paint basics
Paint covers some of the largest areas in buildings, so it is crucial to understand how to specify the right paint for the job and why not all paint is created equally. There are four primary components of paint, and each serves an important role in color and performance. The raw ingredients and formulations can vary widely, resulting in different outcomes for each project.
Solvents used to dissolve or disperse a polymer and reduce the viscosity in paint. A solvent provides no real, added durability benefits and is simply the carrier allowing the painter to get the paint from the can to the surface.
They are the extra ingredients that give the paint specific performance characteristics. For example, mildewcides and rheology modifiers improve the viscosity and application of the coating.
Binders affect everything from stain resistance and gloss to adhesion and crack resistance. Higher quality binders adhere to surfaces better and provide enhanced film integrity and long-lasting performance. Latex paints may contain multiple types of acrylic binders while oil-based contain linseed oil, soya oil, or alkyds.
Prime and extender are the two different types of pigments. Prime pigments provide color and hide. Titanium dioxide is an example of a prime pigment, and it provides excellent light-scattering properties in applications requiring white opacity and brightness. Extender pigments can cost less than prime, and add bulk to the coating, but have little value when it comes to color. These pigments may improve other paint characteristics, including clay, silica, and silicates and calcium carbonate.
When it comes to the final color of the product, it is the result of a color formula combining a base paint with colorants containing primary hue pigments that have been compounded and dispersed into a liquid. Most colorants are added at the point of sale in accordance with a manufacturer’s formula for that specific coating.
To create a high-performing coating that does not sacrifice color requires human and technical expertise to manage hue accuracy and consistency at every stage from product design, quality manufacturing, color formula management, and final tinting to reduce the possibility of color issues on the jobsite. Specifiers should look for coatings, colors, and color formulas that are designed to work as an integrated system. For example, color formulas should be programmed to flex subtly and precisely depending on the product and finish combination specified, ensuring the most accurate color results in the finished product. One way to ensure this is by working with a paint manufacturer that controls their own manufacturing and quality, as it positively affects the colorants used to tint the paint.
How pigments impact performance
Beyond aesthetics, pigments can also provide desirable performance attributes. The type and quality of prime pigments used in the base paint affect the coating’s performance in four areas:
- fading; and
- gloss or sheen.
Hide is the paint’s ability to obscure the surface on which the coating is applied. It is created by the light-absorbing or -scattering properties of pigments. From a practical perspective, ‘dirtier’ colors tend to offer a better hide in fewer coats. Specifiers should look for high-quality paints with an optimal primer for the topcoat color to achieve deep, clear, bright, and translucent hues.
Durability is measured by how well the paint film resists physical degradation from use and environmental conditions, such as abrasion, chemicals, scrubbing, washing, staining, moisture, and ultraviolet (UV) exposure. It is traditionally influenced by the paint’s binder or resin, as well as the gloss level. High levels of resin or binder create high sheen, smooth finishes, and durable surfaces.
This is a result of the paint’s binder imparting adhesion, thereby gluing the pigments together and strongly influencing properties, such as gloss, weather durability, flexibility, and toughness. High paint pigment levels along with coarse pigment granules create duller, rougher, and less-resilient finishes. Color wash-off is the phenomenon of color wearing off the paint film due to repeated cleaning. It is a result of pigment particles being exposed at the surface. Coatings rated with higher durability retain their color and gloss, no matter how many times they are washed.
Exterior coatings must be resistant to fading, as they are exposed to UV rays and other elements. Interior paints can also fade or the color can lighten when the surface is exposed to significant sunlight. Slight fading is acceptable, but it can become more noticeable as the coating ages. Another problem that can occur with some paints is chalking—when the painted surface comes off—causing the color to appear lighter. Certain pigments are inherently better at retaining color, which is why design professionals should have a broader range of hues for interior products than exterior because the former will fade when used outside.
Gloss and sheen are two aspects of the same element. Both strongly impact how a color or finish looks and can affect how the eye sees that hue. Gloss and sheen are measured by reflecting light off of specific angles. Gloss is measured at a 60-degree angle, meaning a beam of light is deflected from 60 degrees off of a surface and back into a receptor. The receptor provides the number of gloss units, from zero to 100. The closer the gloss units are to 100 units, the shinier, or glossier, the paint. Sheen is measured at an 85-degree angle.
Dark glossy finishes tend to look darker than their matte counterparts while light glossy finishes skew brighter and sharper. The light source’s intensity and direction should be factored in as well. Matte colors tend to look darker when viewed from an angle or in low light and can also look quite flat when viewed straight-on and only seem lustrous from an angle. Glossy finishes can look lighter or slightly mottled if the surface is rough, uneven, or has other imperfections. It is also important to understand sheen and gloss are not mutually exclusive—some paints have a gloss value, others have a sheen value, and some have both.
Here are some tips for specifying a product’s gloss and sheen to ensure the end result meets client expectations.