Calculate Pigment Volume Concentration (PVC), Critical PVC (CPVC) from oil absorption, and the Λ (Lambda) ratio that determines finish type. Supports multi-pigment and multi-binder blends.
Core Equations
CPVC (%) = 100 ÷ (1 + (OA × ρ) ÷ K) | K = 100 × binder specific gravity
Blend: OA_eff = Σ(Wᵢ×OAᵢ)÷ΣWᵢ ρ_eff = ΣWᵢ÷Σ(Wᵢ/ρᵢ)
Λ = PVC ÷ CPVC
1. Pigment Volume Concentration (PVC)
Add each pigment/filler and each binder/resin component with its weight and density. Volumes are derived automatically. The optional OA field on each pigment row also feeds the CPVC blend calculation in Section 2 below — no need to re-enter the same pigment twice.
Pigments / Fillers
Binder / Resin + Additives
PVC
2. Critical PVC (CPVC) from Oil Absorption
Calculated from pigment oil absorption (ASTM D281-style, g oil per 100g pigment) and density. For a pigment blend, add each component separately — the calculator derives a weight-weighted effective OA and density.
Using Your Pigment/Filler Rows from Section 1
Fill in the OA field on each pigment row in Section 1 above (weight and density are already there). This card updates automatically — nothing to enter here.
Effective OA = — | Effective ρ = —
CPVC
3. Λ (Lambda) — PVC:CPVC Ratio
Automatically calculated from the PVC and CPVC results above.
Λ = PVC ÷ CPVC
| Λ | Type of finish |
|---|---|
| < 0.5 | Glossy enamels |
| 0.5 – 0.8 | Satin finishing paints |
| > 0.8 | Matte finishing paints |
| 0.5 – 1 | Primers |
| > 1 | Putty and economic paints |
These bands overlap by design (a primer and a matte paint can share the same Λ) — the right target depends on the product category, not Λ alone.
Practical Note
CPVC calculated from a single pigment's oil absorption is a first-pass estimate. Real formulations blend multiple pigments and extenders that pack together and interact — particle size, shape, and distribution all shift the true packing point in ways a weighted average can't fully capture. Measure CPVC directly on your actual pigment blend (via the Asbeck & Van Loo scrub/gloss or oil absorption method) before finalizing a critical formulation. Λ is a design target, not a pass/fail number — pick it based on the finish and performance you want, then formulate PVC to hit it.
Data Sources & References
- Wadgaonkar, K.K., Gadgeel, A.A. — Polymer Science and Technology: Formulae Masterbook, PolymerDNA
- Asbeck, W.K., Van Loo, M. — Critical Pigment Volume Relationships, Industrial & Engineering Chemistry, 41(7), 1949
- Patton, T.C. — Paint Flow and Pigment Dispersion, 2nd Ed., Wiley-Interscience, 1979
PVC: PVC % = SUM(Vpi) / SUM(Vi) x 100. CPVC: CPVC % = 100 / (1 + (OA x rho)/K), K = 100 x binder specific gravity. Lambda: Lambda = PVC / CPVC.
Built by PolymerDNA — more formulation references in the Formulae Masterbook.