Photochromic pigment changes colors when exposed to Sunlight or UV light, and reverts to its original color when sunlight is blocked.
 
Color conversion: From colorless to colored (red, violet, blue, yellow base color)
From one color to another color 
 
Recommended concentrations
For Solvent/water based ink/paint       3~30% w/w (25%)
For plastics injection/extrusion         0.2%~1% w/w (0.5%)
 
Photochromic microencapsulated powder contains 2-5% of photochromic dye and less than 3% of moisture, suitable for solvent or water based ink/paint and plastic injection/extrusion. Average particle size is 3~10um.