Holbein ranks as one of the world's finest lines of professional oil colors. The formulation of each color is modified individually to compensate for the inherent differences in the working characteristics of pigments. The result is an even consistency across the entire palette of color. Holbein maintains its quality standards by test inspection of pigment purity, color tone, applicability and adhesion, physical stability, light stability, thermo-stability, and anti-bacterial stability. Pigments are ground from three to five times as necessary to achieve a universally consistent viscosity. The manufacturing process in each of the preparation, mixing, grinding, adjustment, and filling stages is monitored by reference to optimum quality standards.