Phosphorescent microspheres are 90% spherical and appear to be off-white under ordinary daylight or regular room illumination. However, when the lights are turned off these phosphorescent particles exhibit phosphorescent yellow-green after-glow.

Intensity according to DIN 67510-1:
800 mcd/m² at 1 minute, 180 mcd/m² at 5 minutes, 90 mcd/m² at 10 minutes, 12 mcd/m² at 1 hour, 5 mcd/m² at 2 hours