what is thermochromic pigment
Thermochromic inks or dyes are temperature sensitive compounds, developed in the 1970s, that temporarily change color with exposure to heat. They come in two forms, liquid crystals and leuco dyes. Leuco dyes are easier to work with and allow for a greater range of applications. These applications include: flat thermometers, battery testers, clothing, and the indicator on bottles of maple syrup that change color when the syrup is warm.