Why is one side of Reynolds wrap shiny?

Reynolds Wrap is made of aluminum foil, which has a naturally shiny appearance due to its reflective properties. The shinier side is the result of the foil being rolled and polished during the manufacturing process. This creates a smooth and reflective surface that enhances its ability to reflect light and heat, making it suitable for cooking applications such as roasting, baking, and grilling.

The duller side of Reynolds Wrap, on the other hand, has a matte finish because it has not undergone the same polishing process. This side often comes into contact with the food during cooking, allowing for better heat transfer and preventing the food from sticking to the foil.

Therefore, the shiny side of Reynolds Wrap is a result of the polishing process and is designed to reflect light and heat, while the duller side provides a non-stick surface for cooking.