The Truth About the Black Mark on Your Toothpaste Tube

Have you ever noticed the little dark square on the end of a toothpaste tube? If you've spent any time on social media, you've probably come across claims that these marks are some kind of secret code. According to the myth, the colour of the square tells you whether a toothpaste is natural, medicated, chemical-based, or somewhere in between.

We've been getting asked about this more and more lately, so we thought we'd dig into it and uncover the tooth, the whole tooth and nothing but the tooth.

The theory goes something like this:

• Green = natural ingredients
• Blue = natural ingredients plus medicine
• Red = natural ingredients plus chemicals
• Black = all chemicals

It's a simple explanation, and that's probably part of the reason it's spread so widely online. Unfortunately, it's also completely false.

So, What Is the Black Mark?

It's actually called an eye mark (sometimes referred to as a colour mark or registration mark). These marks are used during the manufacturing process to provide a visual alignment reference for automated packaging machines to correctly orient, seal, and cut the tube.

In other words, it's there for the machine, not for the consumer.

As toothpaste tubes move through production lines at high speed, optical sensors read these marks to make sure everything lines up correctly. Without them, packaging would be far less accurate and efficient.

Why Are They Different Colours?

Another reason this myth has stuck around is that people genuinely do see different coloured marks on different products. The reality is much less exciting.

Manufacturers choose colours that provide enough contrast for machinery to detect against the packaging design. The colour chosen depends on factors such as the tube artwork, printing process and equipment being used. It has absolutely nothing to do with the ingredients inside.

A black mark doesn't mean "all chemicals".

A green mark doesn't mean "all natural".

They're simply different versions of the same manufacturing tool.

What Really Matters

We actually think it's a good thing to be curious about what's in the products you use every day. Instead of looking at the colour of a mark on the end of a tube, the best place to start is the ingredient list and any certifications the product holds.

Our toothpastes are NATRUE certified, which means they meet the strict requirements of the NATRUE standard and are independently audited every year to maintain that certification.

So, the next time you see this myth doing the rounds, you'll know exactly what's going on.

That little black mark isn't telling you what's inside the tube. It's simply helping the manufacturing machinery do its job.

Got a question about toothpaste ingredients, certifications or oral care? Let us know. If you're wondering about it, there's a good chance someone else is too.