Flake White is not useable in water-based media, but works well in oils. It creates a flexible paint film that dries quickly. Although opaque, small quantities do not dominate mixtures, and can help slow-drying pigments to dry. For this reason, it has been a popular mixing white historically; in fact, until the mid-19th century, Flake White was the only white pigment available to artists. Although varnishing is generally considered optional for oil paintings, it is recommended for works containing Flake White, as contact with sulphur in the atmosphere can cause it to blacken. It creates a warm white, which can yellow over time when mixed with linseed oil.
PERMITTED USES: Restoration of art works and protected buildings when alternatives unsuitable.