Re: I figured out how to get balloons to neck EVEN FARTHER!
So you just heat-stretch the neck?
I've done similar things. I own a 3D printer which has a heated bed, which can be set (very accurately) to any temperature up to ~100°C, so I can turn it on and place a balloon on it for a while. I can also leave half of it hanging off the edge if I only want part of it to be heated.