I've already hinted that I did some sprang at the Textile Forum - and it was an utter joy to do. My previous dabblings in this wonderful technique had always fizzled and died before I got to the stage where I could understand what is going on. Add in a few misunderstandings (I had a knot in my brain and didn't really get what the instructions were trying to tell me) and the resulting mistakes, and there is no chance in really getting it at all.
For those of you who have little question marks hovering above your heads - sprang is a braiding technique where you braid on ends (or elements) that are stretched in a frame. You work in the middle, in a shed, crossing threads from the back with threads from the front, and your work grows from the top and bottom edge towards the middle. Once you are in the middle, you have to secure it in some way to prevent unravelling.
This time around, however, sprang finally clicked for me. Plus I finally got to use a ball of lovely cotton yarn that some friends had given me as a present years ago - a single ball of cotton, about 230 m length, so not really a thing to knit with, and not something suitable for historical stuff.
It made a wonderful bag, though:
This is the little bag hanging out next to a 1.5 l bottle of water, for size comparison.
And this picture will show you the amazing stretchability of sprang:
Yes, it will hold four of these water bottles without complaint. It might even hold five, but the cord drawn in at the top (the other place where you have to secure your elements) limits the maximum opening of the bag's top. I think it's still impressive.