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

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

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

Aluminium Foil: Which Side you want to use? - Fine Dining Lovers

Shiny or Dull: What Side of Aluminum Foil's Right?

Chef Tom Kerridge claims that foil should be 'shiny side down' - but do YOU think he's right?

12 Brilliant Uses For Aluminum Foil Around The House

Why Aluminum Foil Is Shiny On One Side While Dull On The Other?

Why Aluminum Foil is Dull on One Side

When using aluminum foil, does the orientation of the shiny side vs. the dull side matter? - Quora

Aluminum Foil: Do you cook with the shiny side in or out?

Aluminium foil - Wikipedia

Why Aluminum Foil Has a Shiny and a Dull Side

Aluminum Foil with Shiny and Dull Side - China Aluminium Foil, Aluminum Container Foil