Folding Tetra-Pack carton (e.g. milk)

Classic

The above is the simplest and fastest way to fold it ~~(as far as I know)~~ (Well see just below…) , And I have been using it for 40+ years…

It got the bonus that you on the folding in step 3, quite easily can get 99% of thick content like yoghurt out!

When placed naturally on a table the open end/corner will be the highest point, so dripping is quite unlikely.

It works just as well for for all sizes independent of the height to width ratio.

As a bonus, almost no force is needed in the foldings (unlike several of below variants) so even useful for people with somewhat weak hands (e.g. arthritis)

It even works with cartons with these damned spouts – though not as elegant as without.

ADD: Variant anno 2019

Recently (in December 2019) I found a new way to fold, that is actually better than the above I have been ‘preaching’ for over forty years… Though the new one is limited to the elongated cartons. It starts like the classic, but the trick is folding the bottom in. Note that the benefits of this one is that it requires (even) less force to fold the bottom in. It also works better with the spouts and drips less.

Note that the compactness depends on the places the two last folds are made. But the more compact the more force is needed to stick the bottom part into the top gap, so find your personal balance. The further upwards you make the top fold the easier. (For spout, it should be on the back on the first image, and obviously on the outside folding on the third, so it ends on top on the last)

If you like drinking milk and can find the depicted variant “Øllingegaard Jersey Hømælk” (Not easy!) I can strongly recommend it, despite large variation, by far the best you can find commercially in Denmark unless you go directly to a farmer with Jersey cows, and yet not all are better… The variation between batches goes frem absolutely exquisite to a few I have simply poured out (but that is less 1%, last time two years ago), but I would say that 80% of the time it is better than what else you can get in Denmark. And it is very rarely as bad as the industrial stuff Arla sells cheap, that dominates the market, but barely are worth drinking.

Variant 1

You can make a prettier ‘shirt like’ model by folding the bottom up symmetric in step 2, and in step 3, fold ½ sides each way backwards – a more complex folding as you are not folding along an existing fold, and you need an extra fold. This variant doesn’t work for the boxes with a plastic spout. But it IS more aesthetically pleasing, and provides a better pocket-like lock of the end than all the others.

Variant 2

Another symmetric variant, that is a bit easier to fold. The idea is squeezing it flat rather than pressing a bottom corner it.

To make this work with a spout we need a little trick at the last step, doing a Z-like double fold. The rather thick fold is quite hard to get into the ‘pocket’ though, and the end is not ‘protected’, though pointing upwards on a table. The folding lines can be adjusted to find a suitable comprise between how hard it is to fold, and how compact it gets. That is how deep the top fold line goes into the ‘pocket’.

A little too hard to make a drawing, so see this collage also (click to enlarge somewhat)

Variant3

It Is possible to make a folding similar to Variant 2 WITHOUT opening the top in step 1, instead start with step 2, from the middle, but additionally press the top down ‘like a roof’. while spreading the sides. One drawback of this variant, is that it is not as suitable for ‘completely’ emptying. And it only works if the height is slightly less than three times the width. So it won’t work for the stumpier versions common in Denmark for ½l and ¼l. BUT for those with a spout guaranteed no dripping. So you could safely put it in a back if you have had a pick-nick.