Paint Types + Chemistry Reference
Overview
Paint chemistry determines which paint to use where. Match wrong + the paint fails. This reference covers the categories, what they're best for, + how they're made.
Paint anatomy
All paint has 4 components:
- Binder / resin - the film-forming polymer (what holds it together)
- Pigment - the color + opacity
- Solvent - the carrier (water or oil)
- Additives - drying agents, mildewcides, surfactants
The binder determines paint type + properties.
Categories by binder
Latex / acrylic (water-based)
- Binder: acrylic polymer (premium) or vinyl-acrylic (mid-grade)
- Solvent: water
- Dry time: touch dry 30 min - 2 hrs; recoat 2-4 hrs
- Cure time: 30 days to full hardness
- Cleanup: soap + water
- Smell: low
- VOC: low (most < 50 g/L; "zero-VOC" available)
- Flexibility: excellent (breathes, won't crack with substrate movement)
- UV resistance: excellent for exterior
- Best for: most interior + exterior residential, ceilings, walls, trim
- Not best for: high-wear surfaces with very specific cleaning requirements
100% Acrylic vs Vinyl-Acrylic:
- 100% Acrylic = premium,, lasts 15-25 years exterior
- Vinyl-acrylic = mid-grade,, lasts 7-12 years exterior
Use 100% acrylic for exterior + high-quality interior. Worth the premium.
Oil-based / Alkyd
- Binder: alkyd resin (synthetic oil-based polymer)
- Solvent: mineral spirits
- Dry time: touch dry 6-8 hr; recoat 16-24 hrs
- Cure time: 30-60 days
- Cleanup: mineral spirits (more difficult)
- Smell: strong VOC odor
- VOC: high (300-450 g/L typically; regulated in many states)
- Flexibility: rigid (cracks with substrate movement over time)
- UV resistance: yellows in sunlight; not best for exterior
- Best for: trim that needs hardness, doors, cabinets, metal
- Not best for: most modern residential (acrylic now matches performance)
Why oil is being phased out:
- Regulations: California, NY, others have banned/restricted high-VOC paints
- Modern acrylics match oil for hardness
- Oil yellows over time (especially whites)
- Disposal regulations
When oil is still right:
- Heavy-duty trim/doors (some refinishers prefer)
- Metal (with rust-inhibiting properties)
- Touch-up to existing oil finish (matching)
Latex-modified acrylic (waterborne alkyd)
- Binder: alkyd in water emulsion
- Cleanup: water
- Hardness: oil-like
- Smell: lower than oil
- VOC: medium
- Best for: trim, doors, cabinets - "hardness of oil, cleanup of latex"
Newer category bridging oil + latex performance.
Shellac
- Binder: lac resin (natural)
- Solvent: denatured alcohol
- Dry time: 30 minutes
- Best for: stain-blocking primer (water, smoke, tannins)
- Premier brands: BIN, Zinsser
- Not for: outdoor exposure, hot surfaces
Use as primer ONLY; rarely as topcoat.
Specialty paints
Epoxy:
- 2-part chemistry mixed before use
- Extreme hardness + chemical resistance
- For: garage floors, basement floors, industrial
- Difficult to apply
Elastomeric:
- Flexible polymer paint
- Bridges hairline cracks (1/16")
- For: exterior stucco, masonry
- Premium pricing
Mineral / lime paint:
- Inorganic binder
- Breathable, durable, expensive
- Historic preservation, plaster
Sheens (within each chemistry)
Within latex or oil, sheens determine reflectivity:
| Sheen | Sheen Level | Use Cases |
|---|---|---|
| Flat / Matte | 0-5% reflectivity | Ceilings, low-traffic walls (touch-ups invisible) |
| Eggshell | 5-10% | Living rooms, bedrooms (gentle wipe-clean) |
| Satin | 25-35% | High-traffic walls, kitchens, bathrooms |
| Semi-gloss | 35-70% | Trim, doors, windows, bathrooms (wash-friendly) |
| Gloss / High-gloss | 70%+ | Trim accents, doors with high traffic |
Sheen rule: higher sheen = more washable + more durable + shows more surface imperfections.
Pigment quality
Premium paints have:
- More pigment (better coverage; less paint needed)
- Better pigment particles (smaller, more uniform)
- Coverage: 350-450 sq ft per gallon (vs 200-300 for cheap)
Why this matters:
- Premium paint with 1 coat = cheap paint with 2-3 coats
- Labor cost dominates total job; better paint = less labor
- Better paint = better final appearance
VOC + environmental
VOC (Volatile Organic Compounds):
- VOCs evaporate during cure; contribute to smog + indoor air pollution
- Regulated:
- California's SCAQMD: max 50 g/L most latex
- Many states: max 100 g/L
- "Zero-VOC" = < 5 g/L
Allergen-friendly / low-emission:
- Greenguard Gold certification
- Important for: hospitals, schools, sensitive customers
Additive specifics
Mildewcides:
- Added for bath, kitchen, exterior
- Modern: copper-based (no longer using arsenic, etc.)
Anti-fouling:
- Coastal exterior paints - resist salt deposit
Insecticide-additive:
- Some premium exterior paints
- Repels termites, ants near foundation
Paint storage
Latex/acrylic:
- 1-2 year shelf life unopened
- 6-12 months once opened (well-sealed)
- Don't freeze
- Store in moderate temperature
Oil-based:
- 2-5 year shelf life unopened
- Once opened: 6-12 months
- Store away from heat (flammable solvent)
Disposal:
- Latex: latex hardens; dispose dry in trash
- Oil: hazardous waste; municipal hazardous-waste site
- Empty cans: recyclable if clean
Common chemistry mistakes
- Latex over oil without prep: latex peels off oil unless surface is sanded + primed
- Oil over latex: usually OK after sanding
- Wrong primer for the topcoat: paint won't bond
- Stain bleeding through latex topcoat: wrong primer (need oil or shellac for water/tannin stains)
- Painting cold: latex below 50°F won't cure properly
- Painting hot: > 90°F dries too fast, doesn't bond well
- Painting humid: > 85% humidity slows cure, can blister
The single biggest paint-spec mistake on residential exteriors: USING VINYL-ACRYLIC INSTEAD OF 100% ACRYLIC. Cost difference per gallon:. Lifespan difference: 7-12 years vs 15-25 years. With labor at to repaint, the cheap paint costs 5-10x more in 15 years. Charge the customer for the good paint + explain the math. They almost always say yes.
References
- Paint manufacturer technical data sheets
- ASTM paint standards
- EPA VOC regulations
- Manuall internal: Interior Painting Process SOP, Exterior Painting Process SOP, Surface Prep for Painting