Color Change Inks and Leuco Dyes

We have been involved with producing materials and products that change color as it relates to temperature (thermochromics) and with the assistance of light (photochromics).  Thermochomic Leuco Dyes will change color based on temperature.  The colors appear while at room temperature and will become clear as the temperature increases.  There are many promotional uses for this product but they are very rarely used in applications with any accurate significance or reporting.