Chromotropic safety threads are threads which have one color in daylight and which have another fluorescence color under Ultra-Violet.
These wires are common in safety booklets and provide a third, more sophisticated level of protection than visible and fluorescent wires
Examples of these threads 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.
