Manufacturing an environmentally sensitive label

摘要

A system for and method of manufacturing an environmentally sensitive label, comprising the steps of selecting an environmental sensitivity characteristic such as temperature, determining a chemical composition required to give the selected characteristic, mixing inactive chemical components according to the determined chemical composition, and printing a label having a portion 4 with the selected environmental sensitivity characteristic. This provides an indicator system which is easy and economical to manufacture and is able to monitor reliably the history of an associated article. Portion 4 is printed using a bubble jet printer with separate reservoirs 18, 20 for the chemical components 22,24. These may comprise an enzyme and an indicator with a base chemical. Chemical selection may be under software control. The colour of portion 4 varies with temperature and time.