Researchers from MIT have developed carbon nanotube stamps that could eventually be used in food and beverage packaging to display information about those items in real time. Though currently a concept, the carbon nanotube stamps are successfully able to print electronic inks onto both rigid and flexible surfaces. Since these inks are electronic, they could be programmed to display things like a countdown to when a food item will spoil or the precise temperature of a hot beverage.
To be sure, the current carbon nanotube stamps are prototypes. However, even with the current system, the MIT process is able to print transistors that could control individual pixels in displays and touchscreens. Since the ink could be stamped at the point of purchase (rather than at the factory,) it is an inexpensive option compared to producing packaging with all this tech built in.