Unicodes can be printing either during rotogravure printing, or slitting.
Rotogravure printing allows for printing 8 pictures next to each other in two lines (250 characters per a line) with ink suitable for direct contact with food. Codes can be placed on a monofilm, or a laminate.
During slitting, we can print unicodes using two heads next to each other. The ink is not fitting for the contact with food.