This is more of a curious question than anything, but what happens when you try to vacuum form over an object that does not lay flat against the surface of the vacuum forming machine top? All the vacuum forming examples I've seen use objects with flat bottoms, so I'm curious to know what happens with the plastic when something does not lay flat.
I ask because I eventually plan to vacuum form this shape (the bigger one) with clear plastic:
As you can see, it doesn't lay flat. I'd have to attach some kind of bottom to it that would sort of fill the gaps between it and the top of the machine.
I'm just trying to learn the limits of what all I can do with vacuum forming.
Someone's knowledge would be appreciated!