I get the message about the can on the side. I've noticed even the HF can holds pressure until the cap collar fractures. Having admitted all that, the thought of it makes me nervous. Gravity is the law! It's the same feeling that I had when switching from paper tape to mag tape. If I couldn't see the holes, how could I believe anything was written on it? (And there have been a few times over the years when I have indeed found a tape I wanted to use be blank).