These inks reversibly change color as their temperature changes.
Thermochromic inks all work the same way.
Below the activation temperature, they are colored. Above the activation temperature they are clear or lightly colored.
As the ink cools, the original color returns. These inks can be modified to change at a variety of different temperatures.
Low Temperature Ink: used for application where a product is chilled and special messaging is wanted. Eg. Beverage labels and ice cream packaging.
Body Temperature Ink: Designed to show color at a normal room temperature and disappear or change color when warmed up. This can be done by rubbing a finger or breathing warm air on the application. Eg. Stickers, labels and receipt tape.
High Temperature Ink: This formulation disappears or changes color when heated up. Eg. Great safety feature on labels for microwaveable products, hot or cold beverages and frozen food products.