Paint and pigment: Colour and performance from design to delivery

Foundation of the paint system

Primers can play a critical role in the success of any paint system and help achieve the final topcoat colour. The primer is a hard-working component which establishes the initial adhesion to the substrate. Certain primers are formulated to block stains, resist corrosion, assure adhesion, allow the finish coat to develop a full and consistent sheen and maintain a topcoat gloss, and act as a surface filler.

For certain deep, vivid, or transparent colours, a grey primer achieves accurate colour match in fewer coatings, better touch-up, excellent hide, a more uniform colour with less streaking, and bolder and brighter colours, resulting in increased customer satisfaction.

It is common to see specifications that call for one coat of primer plus one or two coats of a topcoat, but this may fall short of what is needed to achieve a suitable hide and the desired finish with deep tints and accent colours. Instead, it is important to keep in mind that deep and accent clear-base colours may require one to two more coats to achieve the proper hide. A primer is necessary because it helps contactors avoid applying additional coats of paint, saving them time and money and avoiding issues like uneven paint film or peeling.

How pigments impact performance

Beyond esthetics, pigments can also provide desirable performance attributes. The type and quality of prime pigments used in the base paint will affect the coating’s performance in four areas: hide, durability, fading, and the gloss or sheen.

Hide is the ability of a paint to obscure the surface upon which the coating is applied. It is created by the light-absorbing or light-scattering properties of pigments. From a practical perspective, “dirtier” colours tend to offer a better hide in fewer coats. Specifiers should look for high-quality paints with an optimal primer for the topcoat colour to achieve deep, clear, bright, and translucent colours.

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 UV exposure. It is traditionally influenced by the binder or resin of the paint, as well as the gloss level. High paint-resin or binder levels create high sheen, smooth finishes, and durable surfaces. This is a result of the paint’s binder imparting adhesion, binding the pigments together and strongly influencing properties, such as gloss, weather durability, flexibility, and toughness. High paint pigment levels along with course pigment granules create duller, rougher, and less resilient finishes. When colour has worn off the paint film from repeated cleaning, this is called colour wash-off and it is a result of pigment particles being exposed at the surface. Coatings rated with higher durability will retain their colour and gloss, no matter how many times they are washed.

Fade resistance is typically referenced in regard to exterior coatings since these are exposed to UV rays and other elements. However, interior paints can also fade or lighten when the surface is exposed to significant sunlight. As the coating ages, the fading can become more noticeable and while slight fading is acceptable, some paints can begin to develop chalking—when the painted surface comes off—causing the colour to appear lighter. Certain pigments are inherently better at retaining colour, hence why specifiers will generally have a broader range of colours for interior products than exterior because interior colourants used outside will fade.

Gloss and sheen are two aspects of the same element. Both strongly impact how a colour or finish looks and can significantly affect how the eye sees it. Gloss and sheen are measured by reflecting light off 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 intensity and direction of the light source should be factored in as well. Matte colours tend to look darker 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 that sheen and gloss are not mutually exclusive—some paints have a gloss value, some 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.

Flat

Typically less durable, flat and matte finishes offer zero to very low reflectance when dry and can hide imperfection in the substrate.

Satin

Slightly more durable, low gloss, low sheen, low lustre, and velvet finishes offer low to medium reflectance when dry. Satin finishes can minimize glare in spaces with lots of lights.