The colored squares or rectangles found at the crimped end of toothpaste tubes are often the subject of speculation. These markings are, in reality, registration marks used in the manufacturing process. They serve as visual cues for sensors on high-speed filling and sealing machinery, allowing the machines to accurately cut and seal the tubes at the correct location.
The registration marks play a crucial role in efficient and precise mass production of toothpaste. Without them, the machines would not be able to properly orient and process the tubes, leading to misaligned seals and wasted product. The color itself is typically chosen based on the packaging design to provide maximum contrast for the sensors, ensuring reliable detection and minimizing production errors. This system has been employed in various packaging industries for many years, streamlining the manufacturing process.