Varnish Coverage Calculator — Quantity for Paintings

Varnish (ml) = Area (m²) × Coverage rate (ml/m² per coat) × Texture multiplier × Coats

Typical coverage rates (per coat)

These are heuristic studio figures, not a single manufacturer’s spec — always check your own product’s technical data sheet and use the Advanced override if it differs.

• Spray varnish: 120 ml/m² (≈8 m²/L). Spray uses the most because overspray is lost — Liquitex Professional Spray covers roughly 2 m² per 400 ml can (≈5 m²/L ≈ 200 ml/m²), Golden Archival aerosol gives ≈7–11 m²/L.
• Brush-on varnish: 80 ml/m² (≈12.5 m²/L), within the picture/wood-varnish band (Barrettine PU ≈14, Polyvine ≈15, Ronseal up to 16–20, brushed acrylic ≈6–8 m²/L).
• Retouch varnish: 60 ml/m² (≈16.7 m²/L) — applied as a thin temporary layer, so it uses the least.

Texture multipliers

Raised paint covered from all angles uses more varnish than a flat surface.

• Smooth: 1.0×
• Moderate: 1.3×
• Heavy impasto: 1.6×

Total drying time shown is the wait between coats added up (drying-per-coat × coats after the first); it excludes the final cure.