From flat to high gloss, the quality of a painted surface improves proportional to its sheen. The simplest explanation is in the two primary components of paint: pigments and binding agents. The pigments used in paint insoluble granules, meaning they are small particles that do not dissolve in liquid. The binding agent primarily acts as an adhesive for the pigments. But, it also provides the sheen level, which is the amount of light than can be reflected from a finished surface.
There is little consistency in sheen levels between manufacturers. This is because different manufacturers have different binding agents between them and between different finishes. While there is a formula to determine pigment-volume concentration (PVC), simply reducing the amount of binding agent would be problematic. As less agents are used, different agents are introduced to increase the strength of the paint as it dries.
As described by Golden Artist Colors, different binding agents do affect pigment chroma. This is why the appearance of the same color listed by a manufacturer can be different between binding agents, such as oil, latex, and acrylic. But, for the sake of discussion, the subject will be discussed as only one binding agent.
While pigment may be a constant, fewer binding agents in the paint leave pigments on the surface, creating a rough texture. This allows paint pigments to really stand out and a wall painted in flat colors is something to be appreciated. Its ability to diffuse light also makes it perfect for concealing wall repairs, nail holes, and ghosting, which is being able to see the placement of wall studs behind sheetrock. Flat paint, however, is not for high-traffic areas, behind furniture, or in homes where small, sticky hands might touch it. It’s not child friendly. But if you insist, gently scrubbing with a wet sponge and baking soda will remove crayon from flat wall paint.
Another unfortunate side of flat paint is it allows for the collection of dust and debris. They can be difficult to clean and maintain and are a potential host environments for mold and bacteria. For those reasons, flat and matte paints are not recommended for indoor high traffic areas, kitchens, or bathrooms. Some brands have been able to overcome issues of dust and mold. But otherwise, paint quality is considered proportional to its sheen.
As binding agents are added to a paint mixture, the dried surface becomes less porous. A smooth surface is better protected from elements and therefore, easier to clean. But, it also makes slight imperfections more noticeable. Filled holes from nails, scratches, and dings become more evident. You will see every little imperfection if the wall was not properly prepared before painting. Later paint touch-ups may never quite match. Cracks and chips may occur when something collides with the surface.
There is almost a ritual to preparing a wall for high-gloss paint. Most prepared walls have a Level 4 surface, which describes the minimum necessary requirements to prevent the appearance of seams and nails in the sheetrock in the finished wall. But an enamel, semi-gloss, or high gloss wall requires a Level 5 preparation that includes a skim coat of specially mixed joint compound applied over the whole surface to make the unpainted wall a uniformly flat. On new construction, this can increase the cost of wall preparation by about one-third. But the appearance and quality of a well prepared and properly painted wall could mean fewer costs down the road, particularly because you might be less inclined to risk damaging it.
Sherwin-Williams has 14-sheen levels. But, between our three favorite paint companies—Sherwin-Williams, Behr, and Benjamin-Moore—there are 6-sheen levels: flat, matte, eggshell, satin, semi-gloss, and high gloss. Each is tested similarly with a light placed at 60° and 85°, relative to the painted surface and the reflected light measured with a light meter. This gives us a reasonable guide of what to expect from the finished product. The resulting numbers are expressed as whole numbers on a scale of 0—100. The lower the number, the less light will be reflected by the sheen.
The reflective values provided are not be confused with Light Reflective Value (LRV), which is a scale of 0—100 referencing a color’s appearance. That scale is based on how similar a color is it black or white. It is worth noting there is no true zero on either scale. All surfaces reflect light and therefore, color. For example, Benjamin Moore’s Bright Yellow is available in flat. It has an LRV of 68.7, but it’s sheen level would mean less than 5% of light would be reflected from it.
Use flat paint to create non-reflective surface. This sheen’s ability to diffuse light make it the best choice for well-lit areas like ceilings and offices. It’s ability to bring out the brilliance in cooler hues should not be ignored. However, it’s porous surface can make it difficult to clean.
The difference between matte and flat paints is near indistinguishable. But at 4—10%, it’s decreased PVC makes it easier to clean. This sheen level is appropriate for living rooms and bedrooms.
Eggshell’s 12—15% reflectivity is appropriate for walls high traffic areas, living rooms, and bedrooms.
Satin is one of the more common finishes used in homes today. At 25—35%, it allows a reasonable amount of light to be reflected.
Semi-gloss has a much smoother surface, reflecting 35—60% of the light hitting it. This makes it easier to clean and ideal for painting trim, doors, cabinets, and wood paneling.
The best high gloss paint will reflect as much as 60—90% of the light touching it. With the proper amount of preparation, work, and care, it can be made to shine and reflect discernable features in the room.