Abstract: In methods and systems for activating a label including a thermochromic ink used as a time/temperature indicator, the label has a first or printing section, and a second or thermochromic ink section. A package parameter, such as the weight of a food package or portion, is determined and printed on the printing section of the label. The label is advanced to an activation energy station. At least the thermochromic ink section of the label is exposed to activation energy, such as heat or radiation. The label is then quickly moved to a cooling station. At the cooling station, at least the thermochromic ink section of the label is quickly cooled, to activate the label for use as a time/temperature indicator.