Good call! Will look for clean materials.
Discussion
there is a type of cotton weave, like what is used with bandages, that is knotty and tangled and even without adding elastane or other stretchy rubbery synthetic crap, has a lot of stretch. you can also, a bit more expensive, just get a very large piece of medium weight canvas and cut it across the bias (45 degrees) and it has a lot of stretch in this direction, but is more durable than bandage weave.
also, it's possible to use wool, which is also a naturally elastic material, even silk, when woven, if you cut across the bias, but knitted is better, and it is possible to find heavier knit fabrics, they are stretchy across the "weft" if you can call it that.
Brilliant! Would love to find a place that sells organic non dyed materials / fabrics and either find a seamstress or learn how to sew at some point.
yeah, the thing about making a sling from bias cut is you are going to probably waste like half of the material
oh yeah there is also some more esoteric weaves that have high elasticity, i never learned exactly how it's done but there is this thing called "sprung" and i think it basically works by forming a grid a bit like that fencing grid thing, i forget what americans call it, but each line of the thread is a zig zag which loops back left and right around the adjacent thread.
https://en.wikipedia.org/wiki/Sprang
yeah, sprang, idk, my mother called it "sprung" anyway, point being that it's a perfect way to make a sling for a baby. it would let you use a strong but soft and quite thick gauge cordage while allowing a lot of stretch.
looks like the device you need to make it is fairly simple to build also, probably could be made with broomsticks.