Top Paint Brands Compared: Sherwin-Williams, Benjamin Moore, Behr and PPG
Professional painters do not pick brands by the color chip display. They evaluate paints on solids-by-volume percentage, the refractive index of the titanium dioxide pigment, Krebs Unit and ICI Poise rheology, ASTM scrub cycle ratings, and the chemistry of the colorant system. This guide explains what each of those metrics means and how the top brands — Sherwin-Williams, Benjamin Moore, Behr, and PPG — compare on the numbers.
Why Some Paints Cover in One Coat — and Others Don't
Hiding power — the ability to cover a dark color with fewer coats — is not about how much pigment is in the can. It is about what kind of pigment, and specifically its refractive index relative to the binder that surrounds it. When light enters a dry paint film, it hits pigment particles embedded in the binder. If the two materials have similar refractive indices, the light slides straight through without scattering — the film looks translucent, and you need multiple coats. If the pigment has a much higher refractive index than the binder, the light bends sharply at every particle boundary and scatters back toward your eye — the film looks opaque.
Rutile Titanium Dioxide (TiO₂) has a refractive index of 2.73 — one of the highest of any white mineral. Against the acrylic binder's 1.50, the relative index is roughly 1.82, producing aggressive light scattering and true opacity. Mineral extenders — kaolin clay (n≈1.56), calcium carbonate (n≈1.59), silica (n≈1.55) — have indices barely distinguishable from the binder. The relative index approaches 1.0, meaning the light does not scatter at all. Budget paints replace expensive TiO₂ with these cheap fillers, which is why they require three coats to do what a premium paint does in two. A can of paint at $25 per gallon is not a bargain if you need 50% more of it and twice the labor to apply it.
Solids by Volume: How Much Paint Actually Stays on the Wall
Liquid paint is mostly water (or mineral spirits, in oil-based formulas). When the solvent evaporates, only the solids — pigment plus binder — remain as the dry film. The percentage that stays is called Solids by Volume, and it directly determines how much protective film you get from each coat:
Applied at the same 4.0-mil wet film thickness, a budget paint at 30% solids leaves a 1.2-mil dry film. A premium paint at 42% solids leaves a 1.7-mil dry film — a 42% thicker protective layer from the same application effort. This is why pro painters always ask about solids-by-volume — not price per gallon. The price per dry mil on the wall is the number that matters.
Rheology: Why Some Paints Feel Heavy and Others Glide
The physical feel of paint on a brush or roller is governed by viscosity at two different shear rates. A paint must be thick enough in the can not to slosh out, thin enough under a brush to spread without fighting you, and thick again immediately after application so it doesn't sag down the wall.
| Measurement | Shear Rate | Simulates | Standard Range | Too Low | Too High |
|---|---|---|---|---|---|
| Krebs Units (KU) | Low shear (~200 rpm) | Paint sitting on a vertical wall (gravity) | 85-110 KU | Runs, sags, drips | Difficult to load roller; heavy orange-peel |
| ICI Poise | High shear (~10,000 rpm) | Paint squeezed between brush and wall | 1.0-2.2 Poise | Spatter, mist off roller | Feels gummy, arm fatigue, deep brush marks |
Premium paints use urethane-modified associative thickeners (HEUR) that create a pronounced shear-thinning effect: the paint drops to low viscosity under the brush for smooth application, then rebuilds viscosity slowly enough for surface tension to pull the paint flat — a phenomenon called self-leveling that erases brush and roller marks before the film sets. Behr's formulations, in contrast, tend toward higher ICI viscosity (1.8-2.1 Poise), which is why professional painters often describe them as "sticky" or "heavy" — the hiding power is excellent, but the application is more physically demanding.
Brand Formulation Analysis
Sherwin-Williams — Emerald & Duration
Sherwin-Williams engineers their premium lines around self-crosslinking acrylic polymers — as water evaporates, the polymer chains form covalent bonds with each other, creating a denser, more moisture-resistant film than standard acrylics that simply fuse together without chemical bonding. Emerald Interior achieves roughly 41% solids by volume and balances Krebs Units in the 95-100 KU range with ICI around 1.2-1.4 Poise — low drag under the brush, good sag resistance on walls. Duration uses a "PermaLast" thick-film technology that builds to approximately 2.0 mils DFT per coat, which is why it is popular for exterior applications where bridging hairline cracks matters.
Benjamin Moore — Aura & Regal Select
Benjamin Moore's key chemical differentiator is the Gennex colorant system. Most paint brands — including Sherwin-Williams and Behr — use universal glycol-based colorants. Glycol is a slow-evaporating solvent that stays in the film for days and physically softens the cured binder. The more colorant you add (darker colors), the weaker the film becomes. Gennex replaces glycol entirely with zero-VOC waterborne colorant particles that carry their own cross-linking resin — meaning adding dark pigment strengthens the film rather than weakening it. Aura achieves approximately 40% solids, zero-VOC (<0.1 g/L), and the industry benchmark for color accuracy on dark, saturated hues. Regal Select is the workhorse wall paint — exceptional self-leveling per ASTM D4062 — and the standard that many independent painters stock by default.
Behr — Dynasty & Marquee
Behr (sold exclusively at Home Depot) competes on raw hiding power. Dynasty achieves approximately 44% solids by volume — the highest in category — and loads heavy Rutile TiO₂ for strong one-coat opacity on light-to-medium color changes. The trade-off is rheology: Dynasty measures roughly 104-110 KU and 1.8-2.1 ICI Poise, meaning it feels heavy on the brush and roller. For a DIY homeowner rolling a single bedroom, the extra effort may be acceptable given the lower price point ($55-65 per gallon vs $80-105 for the premium competitors). For a professional painter working 8-hour days, the higher drag is cumulative and real.
PPG — UltraLast
PPG UltraLast is an independent paint store brand (sold at PPG and Dulux locations) that differentiates on ceramic-reinforced polymer technology. The formulation incorporates microscopic ceramic microspheres that increase film hardness and scrub resistance without raising viscosity. At roughly 39% solids, UltraLast has the lowest solids-by-volume of the four brands analyzed, but achieves the highest ASTM D2486 scrub rating (2,000+ cycles) — meaning it is the best choice for surfaces that will be cleaned aggressively, like kitchen backsplashes, mudroom walls, and commercial hallways. Its ICI viscosity (1.1-1.3 Poise) is the lowest in category, making it the easiest to apply by brush — but it requires careful technique to avoid sagging on vertical walls due to its low Krebs Unit range (92-98 KU).
Brand Performance Matrix
| Performance Metric | Sherwin-Williams Emerald | Benjamin Moore Aura | Behr Dynasty | PPG UltraLast |
|---|---|---|---|---|
| Solids by Volume (Φ_solids) | ~41% | ~40% | ~44% | ~39% |
| Primary Pigment | Pure Rutile TiO₂ | Pure Rutile TiO₂ (Gennex) | Rutile TiO₂ + silicates | Rutile TiO₂ + ceramic spheres |
| KU Viscosity (Low Shear) | 95-100 KU | 96-102 KU | 104-110 KU | 92-98 KU |
| ICI Viscosity (High Shear) | 1.2-1.4 Poise | 1.3-1.5 Poise | 1.8-2.1 Poise | 1.1-1.3 Poise |
| ASTM D2486 Scrub Cycles | 1,800+ | 1,800+ | 1,200+ | 2,000+ |
| ASTM D3273 Mildew Rating | 10 (Maximum) | 9 | 10 | 9 |
| VOC Level (EPA Method 24) | <5 g/L (Zero-VOC) | <0.1 g/L (Zero-VOC) | <50 g/L (Low-VOC) | <50 g/L |
| Relative Cost (per gallon) | $80-100 | $85-105 | $55-65 | $70-80 |
The "One-Coat Paint" Marketing Claim
Most retail paint brands advertise one-coat coverage. If you read the technical data sheet fine print, the guarantee is valid only under narrow, idealized conditions: the substrate must be a sealed, primed, perfectly smooth Level 5 drywall surface; the color must be from a small pre-approved palette of high-opacity tints; and the wet film must be applied at 5.0 mils WFT or heavier — a thickness that requires professional-grade roller technique to avoid sags and runs on vertical walls.
In the real world — raw drywall with tape joints, a dark color change, an unprepped surface — one coat rarely produces an even, durable finish. Even when the pigment manages to block the color underneath, a single coat does not build enough film thickness to produce uniform sheen or withstand scrubbing. Professional painters apply two coats of premium paint over a sealed substrate as standard practice, not because the paint is failing to cover, but because the second coat builds mechanical durability and optical uniformity that a single coat cannot achieve regardless of the pigment load.