toothpaste

[Ken200]

Stripey toothpaste How do they get those stripes to come out

[bernardo]

There's an extra bit at the top, round the edge of the hole, where the second colour is squeezed out onto the main bit through small holes. I have read this same explanation quite a few times over the years, and I even took an empty tube apart once to see if I could see the extra bit at the top. It must be fairly small because it was rather narrow and not at all obvious.

[Mortartube]

http://www.straightdope.com/classics/a1_173.html

[bernardo]

Mortartube's link was even better than my own brilliant answer. I'll have to take apart a full tube, and I might find it's easier to see. I might also find that I'm a sad anorak with nothing better to do.

[bernardo]

I took apart a full tube of stripey toothpaste today. To my surprise, I found that there was no mechanism whatsoever of the sort described in the previous answers. The coloured stripes go all the way through the whole tube, ready packed, like in a stick of rock. But presumably there are other manufacturers who use the other method as well. I spread out all of the toothpaste from the tube onto a big sheet of newspaper, and now I am waiting for it to dry, so that I can hang it up and call it art.