Gloss Paint Level Standards

Long gone are the days when paints were available in three categories: flat, semi-gloss and gloss.

Gloss levels marketed by paint manufacturers today are as varied as the paint colors they come in. Consider this short list of descriptors for the range between flat and semi-gloss: silk, suede, low sheen, low luster, low sheen eggshell, platinum, pearl, melamine, velvet, eggshell and satin. Confusing? You bet.

“We found 40 different names between flat and semi-gloss,” says Master Painters Institute (MPI) president Barry Law. “One company creates a new name for gloss level between flat and semi-gloss every year. There’s nothing wrong with that from a marketing perspective, but that creates a great deal of confusion from an industry perspective.”

Traditionally, enamels were oil-based paints. The proper and appropriate definition of enamel is a hard, glossy surface. Today an enamel can be either a latex or an alkyd. It can be a low gloss or a high gloss. “It’s whatever the marketing person decides,” says Law.

To eliminate all this confusion, MPI set out to create reliable gloss level categories. Using these standards, specifiers and applicators can choose a gloss level and know what they’re getting every time, regardless of manufacturer. This information is available on the MPI Web site at www.paintinfo.com and in MPI’s Architectural Painting Specification Manual, also available online.

Many professionals responsible for writing specifications for a project — including architects, engineers and interior designers — rely on MPI gloss and sheen standards. The standards have been adopted by the U.S. Department of Defense as part of its Uniform Facilities Guide Specifications. The standards have also been adopted by the government of Canada, the Veteran’s Administration and the American Institute of Architects.

For Greg Boshard, owner of Combined Painting in Vancouver, BC, adherence to MPI gloss and sheen standards benefits the customer first and last. “It’s about quality assurance,” Boshard says. “You don’t want to use the wrong product. We use the manual extensively when we’re writing specs for customers.”

Figure 1. Gloss is measured at a 60 degree angle from the perpendicular.

Gloss vs. Sheen
Although “gloss” and “sheen” are often used interchangeably, it is important to understand the difference between the two terms. Gloss is measured on a scale of 0 (no gloss) to 100 (perfectly mirror-like). Gloss reflectance is typically measured by deflecting a single beam of light at a 60 degree angle off a surface. The light is deflected into a receptor, which gauges the intensity of that light in gloss units. The higher the number of units, the shinier the surface. This method is useful for evaluating all but the lowest and highest gloss levels (see Figure 1).

Sheen is used to describe the low angle gloss (85 degrees from the perpendicular or 5 degrees above the plane) of a surface. Variances in the sheen of a surface are most noticeable in low gloss coatings. This method is especially useful for measuring the transition between flat and eggshell.

Because gloss is a property of reflected light, it can influence the visual color of a surface when viewed from various angles. This is commonly seen where coatings tinted to the same color, but with different gloss levels, are applied side by side on the same substrate. Ideally, wall coatings should be used that have the same or a very similar gloss reflectance at both 60 degrees and 85 degrees.

Figure 2. Eight brands of white, eggshell latex varied in gloss units from 3 to 9. Most were below 5, a typical measurement of gloss for flat paints.

Gloss levels vary widely among manufacturers
To establish standards for gloss reflectance, MPI conducted an intensive lab study of more than 100 samples of eight brands of premium paint. Five of those brands were produced by multinational paint manufacturers and three were produced by regional manufactures (small, medium and large). Information on the study, as well the tables and figures presented here, are available on the MPI web site at www.paintinfo.com.

“We did the study first in white,” says MPI’s Law. “We then followed up by doing it in pastel, medium base and an accent or deep base, and we found the results even more astonishing. There was absolutely no consistency at all.”

MPI studied latex and alkyd paints in both eggshell and semi-gloss. Study results showed that latex eggshells varied considerably from alkyd eggshells.

MPI measured the gloss levels of eight brands of white, eggshell latex at 60 degrees (see Figure 2). The gloss level varied from 3 to 9 units. None measured 10 gloss units or higher and most measured under 5 — a flat paint by most standards.