Recycling Magic

There were interesting comments on my earlier post about turning plastic bags into plarn. Some referred to ways of using plarn - sleeping mats, shopping bags... Stringy Dogs commented that there is a way of cutting bags so that they form a single big circle, rather than a lot of little circles. She didn't give any details. But I remembered a 'magic trick' that we used to do as children, folding and cutting a piece of paper in such a way that it opened into a big circle that could be put over your head. Several bags and pieces of paper later, it was clear that I had forgotten how to do it! I looked up on the internet and found this post. Aha. So I cut the bottom and handles off a bag, then cut one side open, so I had a single, folded piece, and cut from this side and that:

The middle bit on each 'pair' has to be cut, (except the first and last!) otherwise you get a concertina shape:

And then it can be opened up into a big circle:

It's a bit jagged and I'm not sure it's the most practical way to cut the bag. And it's probably not what Stringy Dogs was thinking of! But there you go, it's possible.