Which side of Reynolds Wrap® Aluminum Foil should I use, the shiny or the dull side?
Actually, it makes no difference which side of the aluminum foil you use—both sides do the same fine job of cooking, freezing and storing food. The difference in appearance between dull and shiny is due to the foil manufacturing process. In the final rolling step, two layers of foil are passed through the rolling mill at the same time. The side coming in contact with the mill's highly polished steel rollers becomes shiny. The other side, not coming in contact with the heavy rollers, comes out with a dull or matte finish.