Cecil has an old column explaining how old toothpaste tubes achieved stripes with a special nozzle. However, as subsequent threads have pointed out, that approach is no-longer used and modern toothpaste achieves stripes with a normal nozzle.
More shockingly: In this video, the creators cut open the back of a toothpaste tube and mix the contents with a knife so that the white and black ingredients appear to be blended HOWEVER when the tube is squeezed, the stripes return.
In the video, the creators later wash out the tube and show that the nozzle is normal and doesn’t have any separator devices.
I have searched the related threads but have been unable to find a satisfactory answer to account for the aforementioned phenomena.
The way I’d do it: Prepare a tube by only mixing the toothpaste in the cut-end half of the tube, about half-way down. Leave the toothpaste at the nozzle end undisturbed. When the camera leaves the subject to show the toilet, the actor swaps the tube he mixed on-camera for the pre-prepared tube. He squeezes out the undisturbed striped toothpaste into the toilet, then displays the toothpaste that had been mixed.
This is in German, but the visuals are all you need. Basically, the colored paste goes in the bottom (top?) of the tube, and there’s a “straw” with small holes that feeds the colored stripes onto the while paste.
There were far too many cuts in that video. I would want to see it filmed all in one take to give it any credence.
And even if they were honest, it was dumb to let all that toothpaste spill out of the cut side. After stirring, they should have folded it over and then clamped it. And then film the entire long stripe coming out of the entire tube until they emptied it.
That IS a striped toothpaste. I paused the video in the supermarket and was able to read the box: “Colgate Optic White with Charcoal”. Google it, or search on Amazon.
Regardless of the brand of toothpaste, I want to be clear that the illusion shown in the video can be made by preparation, misdirection, and taking the camera off of the tube (which happened).
Yeah, it’s a TikTok video. It’s clearly just a bunch of horseshit – or rather a trick of some sort or simple lying and switching toothpaste tubes out. I mean, go out and buy some of that toothpaste, mix it up, and see what happens. I bet it does not come out striped again.
Both Colgate and a dentist posted that “Different color stripes have the same rheology which means when you apply pressure they in the same size and thickness in the tube when you squeeze the tube the toothpaste yield and the tube becomes thinner…because of a phenomenon called thixotropic rheology…when you remove pressure it regains its initial size and thickness and looks like a cylinder of stripes on your toothbrush”.
And the consensus is the ‘mixed’ experiment was faked.
I mean, that much was obvious from the demeanour of the participants. I didn’t even get as far as watching the bit about the toothpaste, the reek of bullshit drove me away before that point.
