Thermochromic inks are special types of inks that change color in response to temperature changes. These inks contain pigments that react to heat, allowing them to shift from one color to another when exposed to different temperatures. This property makes them useful for various applications, including packaging, toys, and temperature-sensitive labels. When the temperature rises or falls, the molecular structure of the pigments in thermochromic inks alters, leading to a visible color change. This technology is often used in products like mugs that change color when filled with hot liquids, providing a fun and interactive experience for users.