New MPI gloss levels study 'spotlights' industry problem!

Some time ago, we began to get a number of e-mails and phone calls about the lack of standards in our industry relating to gloss/sheen levels. There also appears to be gloss and sheen confusion in our industry. Some of these calls came from architects, some from specifiers, and some from major government and professional property management sources. They contacted us because of our technical manuals and references to standards on our web site.

Since that time we began to gather more information and have now prepared two "Caution Note"s on the subject(s); one on the impact of accent colors and one on the subject of gloss/sheen confusion in the industry. Reaction has been strong along the same lines as that expressed by the phone callers and e-mailers.

We then started a lab study to get a 'handle on the problem'. Phase 1 of this study is now complete. It involved well over 100 samples from 8 brands of "premium" paint. Five of these brands belong to major multinational paint manufacturers and three are from regional manufacturers - small, medium and large. We are beginning to see a very large 'challenge'!

Our study involves "eggshell" and "semi-gloss" in both latex and alkyd. Results from our study suggest many of the latex "eggshells" vary considerably from the alkyd versions. We found a large number of other 'anomalies'. When whites are tinted to light, medium, and 'deep' or accent colors, further 'challenges' also arise.

The MPI lab tests were done with films applied to sealed Leneta charts by means of a Bird Applicator with a 3 mil gap. Measurements were taken daily of all specimens at both 60 and 85 degrees for 28 days and 3 averaged measurements were taken at 7, 14, 21, and 28 days to further verify test results. All curing took place in room temperatures from 68 to 72° F.

All measurements were taken with calibrated BYK Gardner micro-TRI-gloss - "state-of-the-art" test equipment.

Against the backdrop of some of the following charts, please bear in mind that the levels for eggshell (both latex and alkyd) vary (from most industry sources) from 10 to 30 units @ 60°. These are, however, distinctly different from most manufacturers data sheets for latex eggshell. Many now list 85° ranges only.

Our first chart is the gloss levels of the eight brands of white, eggshell latex.

Chart 1








Note that none of the 8 samples are 10 gloss units or higher, and that most are under 5 units (a "flat" by many).

Our second chart contains the same 8 white, latex eggshells but with the addition of tinted (by the manufacturers) samples to the same selected colors from a Pratt & Lambert color fan representing pastel, medium, and accent colors. (This represents how a contractor might receive a specification, then have his paint supplier "tint to match".)

Chart 2








Note that none yet meets 10 units, and that now even more are under 5 units. Note also that some manufacturer's accents are below their whites, and some are above.

Our third chart is the same 8 brands - 4 colors measured at 85 degrees.

Chart 3










Note that the vast majority of the samples of 8 brands - 4 colors are now between 10 and 30 gloss units.

Our fourth chart now compares these same latex paint samples with those whose gloss/sheen is also called "eggshell" but which are formulated as alkyds. These samples are with the same 8 brands and the same 4 colors.
[The latexes are in series 1 on the left half of the chart, and the alkyds are in series 2 on the right half of the chart.]

We include the eggshell alkyds because an architect, a specification writer, an interior designer, a property manager, and others, consider the gloss/sheen of eggshell whether latex or an alkyd. When selecting an "eggshell" product, they do not anticipate a difference between the gloss levels of latex and the levels of an alkyd.

Chart 4









Note that all of the eggshell latexes are under 10 units and that most are under 5 units, while most of the eggshell alkyds are between 10 and 25 gloss units! Note also that the discrepancy noticed with the latexes (i.e. where some manufacturer's accents were below their whites and some were above their whites) continues with the alkyds!

In chart five, we see the same comparisons as in chart four but measured at 85 degrees.
[Again the latexes are in series 1 on the left of the chart, and the alkyds are in series 2 on the right.]

Chart 5









Note again the wide discrepancy between the eggshell latexes and eggshell alkyds. Note also that only one brand (with the exception of the accent latex) has any consistency between latex and alkyd. The other interesting aspect is the lack of gloss/sheen consistency that most manufacturers have within their own 4 colors whether measured at 60 or at 85 degrees.

Our last chart is of semi gloss not of eggshell, using the same 8 brands - 4 colors.

Chart 6

Note that the tremendous discrepancy between eggshell latex and eggshell alkyd gloss levels was not found with semi gloss latexes and semi gloss alkyds, and note that brand consistency of gloss within their four colors has improved markedly. There is also a greater degree of consistency between many manufacturers' gloss ranges when comparing that same manufacturer's latexes and alkyds.

Some of the industry confusion is that the terms gloss and sheen are often used interchangeably in some circles. Gloss is generally measured at 60 degrees and sheen is generally measured at 85 degrees accordingly to ASTM "for an otherwise matte specimen" - "most frequently when specimens have 60 degree gloss lower than 10". Although the National Paint and Coatings Association gloss ranges are quoted in some areas (eggshell 5 to 20 at 60° and satin as 15 to 35 at 60°), the NPCA now advises that they have abandoned maintaining their publications on gloss levels. A national retailer's association refers to the Federation of Societies for Coating Technology (eggshell 20 to 30 at 60° and satin or silk overlapping eggshell or semigloss). The FSCT, however, now uses an 8 level numerical gloss category system previously "under consideration" by ASTM, where eggshell is equivalent to level III - 10 to 25 at 60°, preceded by level II which is a high sheen flat and followed by 3 levels of semi gloss.

Other confusion comes from marketing concepts of some paint manufacturers who use an entire array of terminology to define products between flat and semi gloss - terms such as silk, suede, satin, velvet, eggshell, low sheen, low luster, melamine, platinum, pearl, etc. etc.

    We assume the dilemma facing the manufacturers is that:
  • the contractors and applicators who buy the product prefer a lower gloss level (touch up is better, imperfections in drywall finish don't show as much, etc., etc.)
  • many designers prefer the aesthetics of the lower gloss/sheen finishes
  • most owners want higher gloss levels to minimize abrasion and marring, while providing lower maintenance costs from higher scrubability and resistance to cleaning.

The situation is, however, very confusing.

To specifiers and property managers who think they want what they perceive as an "eggshell", are they aware that the term will vary considerably in gloss units between latex and alkyds? Are they aware that the term may well vary considerably in gloss units depending upon their selection of color? Does anybody care what name the manufacturer uses to market its product as long as it is known what gloss level category the product falls into?

The MPI believes that manufacturers should be able to market their product(s) under any descriptive name that they like. The MPI believes that the specifying authority and other design professionals and owners should be able to know what "eggshell" means regardless of chosen color or chosen paint type. The MPI believes that there should be standards where paint products can be categorized regardless of the name given to them by manufacturers.

We propose gloss unit levels in categories - using MPI category names - so that manufacturers listing in the MPI Approved Products List can continue to use any name their marketing people wish, but would then qualify according to MPI standard categories with the standardized gloss/sheen levels. In this way, architects, specifiers, and property managers would have easy-to-identify standards somewhat familiar by their natural namesakes (e.g. velvet, eggshell, satin - in order of their natural gloss and sheen).

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