Why Is Tin Foil Shiny On One Side?

15 May 2018, 16:14 | Updated: 15 May 2018, 16:48

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Mystery Hour Question

Name: Weigong, Bristol

Question: Why is tin foil shiny on one side?

Qualification: Packaging technologist

Answer: When tin foil is produced, the aluminium is rolled between consecutively narrower rollers to attain the correct thinness of the foil.

Because the gap is so narrow, its doubled over so the foil doesn’t tear and so the rollers don’t have to be so accurate, the double side is where its backed onto itself and the shiny side is against the roller.

James' Answer: If you’re making something out of melted stuff, imagine a small pan of melted chocolate and imagine a glass flat chopping board.

Pour the chocolate onto the chopping board try and even it out, wait until it sets.

One side of the melted chocolate that is adhering to the glass chopping board looks shiny and silky, and the side on top looks normal.

Swap the chocolate for aluminium foil. That is the manufacturing process of foil, demonstrated by the use of chocolate.