Chromotropic security fibers are fibers which have one color in daylight and are therefore visible in the paper and which have another fluorescence color under Ultra-Violet.
These fibers are common in security documents and provide a third, more sophisticated level of protection than visible, fluorescent fibers of the same color.
Examples of these fibers are:
- visible in daylight blue and fluorescent green or red,
- visible in daylight green and fluorescent yellow or red,
- visible in daylight yellow and fluorescent blue or green or red,
- visible in daylight orange and fluorescent green or red,
- visible in daylight red and fluorescent blue or green,
- visible in daylight purple and fluorescent blue or red.