Aluminum Foil.
There is a shiny and dull side which occurs during the manufacturing process. Which side do YOU use? I believe the shiny side reflects heat better so to keep food warm I face the shiny side INSIDE. That's just the way I feel about it and I do it all the time! I came across some resistance to my preferred method of cooking this past weekend. Which, led to a series of loud/heavy "discussions" until we finally had access to outside knowledge....we decided to ask a Scientist but the answer was still vague.... maybe it doesn't matter, but I'm still sticking to my theory.
