The best miniature paints share three common traits: pigment density, flow control, and opacity. Because miniatures are small, you cannot afford to have thick, globby paint that obscures fine detail. High quality miniature paints contain finely ground pigments that allow you to apply thin, smooth layers without losing the definition of the sculpture. Furthermore, the viscosity is balanced so the paint flows easily from the brush while staying exactly where you place it. This combination of properties is what separates professional hobby paints from standard craft products, allowing you to achieve smooth gradients and sharp highlights with ease.