Why does aluminium foil have a shiny and a dull side?

How to Use Aluminum Foil the Right Way

What's wrong with the aluminum foil in Vietnam? I have lived here 12 years and always wondered why some brands of foil always come out like this And if it's safe to

Should The Shiny Side Of Aluminum Foil Be Up Or Down When Cooking?

People are just realising what you should use each side of tin foil for

The Reason Aluminum Foil Has Both A Shiny And Dull Side

Should You Use the Shiny or Dull Side of Aluminum Foil? – LifeSavvy

Aluminum Foil: Is There A Right Or Wrong Side?

The Real Reason Aluminum Foil Has a Shiny Side and a Dull Side

Why aluminum foil is shiny on one side

Shiny or dull side of aluminium foil: Which do I use?

Should You Use Aluminum Foil With The Shiny Side Up Or Down?

Why Does Aluminum Foil Have a Shiny Side and a Dull Side?

Mistakes You Should Avoid Making With Aluminum Foil