do you have to put aluminum foil on a baking sheet for the oven?
No, but if it isn't an insulated baking sheet, foil will go a long way in preventing burning on the bottom(As in cookies for exampleOr anything else, for that matter)You DO want to put oil or cooking spray on the foil, thoughNothing is more distressing than finding little bits of foil attached to one's food.
I would look up aluminum structures That would be the lightest I can think of
