speaking of penny stoves, not sure if others do this, but I never really liked the bottom of a can as a base for my penny stove. I just cut out a circular piece of a paper milk carton, the stuff is like a really thick card stock that's wax coated, to use as the base, and it's the right size to use as a cover/cap for the stove when it's not in use as well. Insulates from cold surfaces, doesn't burn, the waxy coating keeps it from getting soggy.

might even be a smidge lighter too, but it couldn't be more than a fraction of an ounce...