Photochromes

P Series: A range of dyes with good solubility in a range of solvents. In solution they are colourless, but on contact with daylight they will become coloured. Typically they can be added to a formulation at less than 0.1% (total formulation weight) to good effect. A range of colours is available:

P101 Cerise	P107 Orange	P111 Yellow	P131 Indigo	P132 Blue

The right side only of these plaques has been exposed to bright sunlight whilst the left side has remained covered.

	Product	Fade Speed	Colour Strength	Fatigue Performance
	P101 Cerise	Fast	Very strong	Good
	P107 Orange	Medium	Strong	Good
	P111 Yellow	Medium / Fast	Medium	Good
	P131 Indigo	Medium	Very strong	Good
	P132 Blue	Fast	Medium	Reasonable

Note: Colour may vary depending on medium.