Toothpaste tube colour mark

How to read it

The small coloured square or bar on the crimped end of a toothpaste tube is an eye mark, also called a colour mark. It is printed so that a light-beam sensor can find it as packaging moves through machinery at high speed. Auber, a tube maker, explains that on a high-speed line the sealing machine uses it to tell when and where to heat-seal the end of the tube. The mark is made for the machines on the production line, not for shoppers, and the same kind of mark appears on milk packets and cream sachets, according to Dubai Municipality.

Also searched as: color mark, eye mark, toothpaste color code.

The colour-code rumour

A message shared widely online claims the colour of the mark shows what the toothpaste contains: black for pure chemical, red for natural and chemical, blue for natural and medicinal, and green for natural. It is false. In 2016 Dubai Municipality’s Public Health and Safety Department answered the rumour: Dr Mariam Mahmoud Bin Eisa, head of its Field Inspection and Consumer Product Safety Section, said the colours have no relation to the products’ components. Snopes reached the same conclusion, adding that “natural” and “chemical” are too vague to mean much, since natural products are made up of chemicals too.

Why the colour varies

Eye marks are not limited to green, blue, red and black. Snopes notes that different colours go with different types of packaging or sensor, and Dubai Municipality says the choice of colour is the company’s. What the machine needs is a mark it can pick out: Auber warns that a mark that is too small, too low in contrast, or placed in a busy printed area can be misread, leading to skewed or misaligned seals.

Where the ingredients are listed

What a toothpaste contains is printed in the ingredients information on its box or tube.