Old Canaan Building Materials

Casein paint and milk paint are often discussed as if they are the same material, and they are related but not identical. Both use casein — the principal protein in milk — as a binder, but casein paint as a distinct commercial category typically refers to a more refined, more consistently performing formulation than the traditional farmhouse milk paint recipe, and it has its own specific working properties worth knowing.

Casein paint dries to a completely flat, chalky, absorbent finish with no sheen whatsoever — flatter than the flattest modern latex paint. The color has a particular depth because the paint does not form a reflective film; light is absorbed rather than bounced back, producing a quality some painters describe as velvety.

Casein paint is a water-based paint using purified casein protein, often combined with lime, as the binder, with pigment added for color. Commercial casein paints are more refined and standardized than traditional milk paint, which is mixed from raw milk protein and can vary batch to batch. Old Fashioned Milk Paint Company and Real Milk Paint Company produce both traditional milk paint and more refined casein-based products.

Casein paint is not washable or scrubbable in the way a modern latex or alkyd paint is — its flat, absorbent finish is part of its character but also its limitation. It is correct for walls and ceilings in low-traffic, low-moisture rooms. It is not correct for kitchens, bathrooms, or high-traffic surfaces without a protective topcoat.

Casein paint produces an interior wall finish with a depth and quality that no modern paint technology replicates, correct for historically sensitive interiors where the period finish character matters. It is a finish choice for rooms where its limitations — no scrubbing, careful application — are acceptable trade-offs for its appearance.

Old Fashioned Milk Paint Company and Real Milk Paint Company both offer casein-based and traditional milk paint products through their websites and specialty dealers. Mixed fresh from powder for most products; follow manufacturer mixing ratios precisely.