you said: The truth is that the shiny side is not treated with a dangerous chemical. Mineral oil is used as a lubricant during the rolling process, some trace of which may remain on the finished foil — but it’s not dangerous. The shiny side is shiny because of the way foil is made. During the last pass through the rolling mill, a double thickness of foil is run between the rollers. The side of each sheet that comes in contact with the polished steel rollers comes out shiny. The other side has a matte finish.
Follow up question:
If the metal runs “between the rollers” wouldn’t both sides of the metal come in contact with a roller?
Seems more likely to me that one roller is polished and the other purposely transfers a matte finish to the other side.
Welcome to the Straight Dope, mfergurson. When you start a thread about a column, it’s customary to include a link, since the board software doesn’t do it for you, and we all want to know what we are talking about so there’s no misunderstanding.
what is being discussed is aluminum foil used for cooking. metal foils for other purposes might have a single thickness run through rollers and shiny on both sides.
