Once ink reaches a predetermined temperature, it will change color in seconds and will remain that color permanently. Thermal Locking Ink can also be used to render any bar code unscannable if the product is no longer fit for purchase due to overheating. Thermal Locking Ink is rated as GRAS for human consumption.
Thermal Trac: Color-changing labels
Relying on a revolutionary ink called Thermal Locking Ink (Patent Pending), Thermal Trac labels help determine if a product has been damaged due to exposure to heat.
Apr 13th, 2017