According to our statistic database, the general duration of colour changing effect of each thermochromic pigment ranged between 4000-8000 times. Consisting of organic substances, the themochromic colour could be effective averagely for two years. However, when storing at lower temperatures such as 4oC, it is possible to extend the lifetime of thermochromic pigment. Definitely avoid sunlight/ UV light contact with the thermochromic pigment, which will largely shorten its lifetime.