Architectural Paints
The interior and exterior paints, primers and enamels used on homes and commercial buildings — what is in them, how sheen and quality differ, and how to specify them.
Key takeaways
- Architectural paints are field-applied coatings for buildings; waterborne acrylic latex dominates both interior and exterior use.
- Sheen, binder quality and pigment volume determine washability, touch-up behavior and durability more than the label’s marketing claims.
- Primers solve specific problems — porosity, stains, adhesion, alkalinity — and should be chosen for the substrate.
- VOC regulations vary by region and have reshaped formulations toward low- and zero-VOC products.
- Most repaint failures trace to preparation: dirt, gloss, chalk, moisture or incompatible old coatings.
Architectural paints, sometimes called trade sales or decorative coatings, are the paints sold through paint stores and home centers and applied on site to residential, commercial and institutional buildings. They protect and decorate drywall, plaster, wood, masonry and metal in environments that are mild compared with industrial service. Their performance demands are still real: scrubbing in hospitals and schools, sunlight and rain on exterior walls, humidity in bathrooms, and the expectation that a wall can be touched up invisibly years later.
The line between architectural and industrial maintenance coatings is blurry. Epoxies and urethanes appear in commercial interiors, and many paint stores sell light-duty industrial products. This article focuses on conventional building paints.
What is in a can of paint
- Binder — the film-forming resin. Most modern products use acrylic or vinyl-acrylic latex; see acrylic coatings. Solvent-borne alkyds remain in some enamels and primers, and waterborne alkyds and urethane-modified acrylics are used for hard, leveling trim finishes.
- Pigments — titanium dioxide provides hiding; colored pigments provide tint; extender pigments such as calcium carbonate, clay and silica control sheen, cost and texture.
- Liquid carrier — water in latex paints, mineral spirits or other solvents in alkyds.
- Additives — thickeners, dispersants, coalescents, defoamers, mildewcides and in-can preservatives.
The ratio of pigment to binder, expressed as pigment volume concentration (PVC), largely sets sheen and durability. Flat paints carry a high PVC, which hides imperfections but leaves a more porous film; glossier paints carry more binder, producing a tougher, more washable surface.
Sheen levels and where to use them
| Sheen | Look | Washability | Typical uses |
|---|---|---|---|
| Flat / matte | No shine; hides surface flaws | Low to moderate (better in premium “washable matte”) | Ceilings, low-traffic walls |
| Eggshell | Soft, low luster | Moderate | Living areas, bedrooms, offices |
| Satin | Smooth, pearl-like | Good | Hallways, kids’ rooms, kitchens, exterior siding |
| Semi-gloss | Noticeable shine | Very good | Trim, doors, bathrooms, cabinets |
| Gloss / high gloss | Reflective | Excellent | Doors, railings, accent trim |
Sheen names are not standardized across manufacturers, so one brand’s satin may be glossier than another’s. Specifiers often reference the Master Painters Institute (MPI) gloss level categories to remove ambiguity. Gloss is measured with a glossmeter at standard angles, as described in gloss and color measurement.
Primers, finishes and specialty products
Primers and sealers
Primers are formulated to bond and seal rather than to look good. Common types include drywall primers that equalize porosity between paper and joint compound, stain-blocking primers (often shellac, alkyd or specialty waterborne) for water stains, smoke and wood tannins, bonding primers for glossy or difficult surfaces, and alkali-resistant primers for new masonry and stucco. Masonry-specific considerations are covered in coating masonry and block.
Interior and exterior finishes
Interior paints emphasize hiding, scrub resistance, low odor and touch-up. Exterior paints need flexibility to move with siding, resistance to UV and chalking, mildew resistance and dirt pickup resistance. Specialty products include elastomeric wall coatings, dry-erase finishes, antimicrobial coatings for healthcare, and direct-to-metal acrylics for light-duty steel.
Measuring quality
Price is a rough proxy for binder content and pigment quality, but published test data are more reliable. Useful properties to compare include:
- Scrub resistance, commonly measured with ASTM D2486, indicating how well a film survives repeated cleaning.
- Hiding power (contrast ratio), which affects the number of coats needed.
- Volume solids, which determines dry film per coat and true coverage; use the coverage calculator in our tools.
- Block resistance, important for doors and windows that close against painted surfaces.
- Stain removal and burnish resistance for high-traffic interiors.
Typical spread rates for architectural paints fall around 350–400 ft² per gallon (roughly 8.5–10 m² per liter) on smooth, sealed surfaces, and considerably less on porous or textured ones. Always follow the product data sheet.
VOC rules and indoor air
Architectural coatings are regulated for VOC content in many regions, including the U.S. EPA’s national architectural coatings rule, California air district rules such as SCAQMD Rule 1113, and EU limits under the Paints Directive. These rules set category-specific limits that differ by jurisdiction, so a product legal in one state may not be sold in another. Background is in VOCs and coating regulations. Low-VOC and zero-VOC labels refer to the base paint; colorants can add VOCs unless they are also low-VOC.
In the United States, homes built before 1978 may contain lead-based paint. Sanding, scraping or heat-stripping can create hazardous dust, and renovation work in pre-1978 housing and child-occupied facilities is regulated by the EPA’s Renovation, Repair and Painting Rule. See lead paint hazards before disturbing old paint.
Preparing for a repaint
- Inspect. Look for moisture sources, peeling, chalking, mildew and cracked caulk; fix leaks first.
- Clean. Wash away dirt, grease and mildew; rinse thoroughly.
- Remove loose paint. Scrape and sand to a sound edge, feathering transitions.
- Repair. Patch holes, recaulk joints with paintable sealant, and spot-prime bare wood, metal and patches.
- Dull gloss. Scuff-sand or use a bonding primer over glossy enamels, especially when switching from alkyd to latex.
- Apply finish coats. Two coats generally give more uniform color, sheen and durability than one heavy coat.
Frequently asked questions
Is “paint and primer in one” a real primer?
These products are typically high-build, high-hiding paints that self-prime over sound, previously painted surfaces. Stains, bare wood, bare metal and glossy surfaces usually still need a dedicated primer.
Can latex paint go over oil-based paint?
Yes, if the oil-based paint is clean, dull and sound and a bonding primer is used where specified. Applying latex directly over glossy alkyd often leads to peeling.
How long does exterior paint last?
It varies with climate, exposure, substrate and preparation. Well-prepared surfaces with quality acrylic paint commonly last many years, while south- and west-facing walls usually weather fastest.
Educational reference. Coating performance varies by formulation. Always follow the manufacturer’s product data sheet, safety data sheet and your project specification.
