GOLDEN Phosphorescent Green is a water-based acrylic medium that can be applied to various surfaces. The unique pigment used in its formulation is characterized by its ability to absorb and store natural and artificial light. When the light source is removed (i.e.: when the lights are turned off or the painted object is taken into a dark area) a bright, greenish glow is emitted for up to 15 minutes. The glow steadily diminishes as the stored light energy is released.