Shiny aluminum foil??

Bzzzt!    Nice try, but wrongo, at least for "Reynold's Wrap".  Duralumin is mainly used where strength is required.  It's rather expensive as it has to be heat-treated.   And it still doesnt explain the shinyness, IIRC duralumin can get mighty gray too.  The straight info

from Reynold's wrap:

In 1919, the U.S. Foil Company, parent of Reynolds Metals Company was founded in Louisville, Kentucky to produce lead and tin foil. Then in 1926, the company entered the aluminum business, rolling aluminum foil for packaging. Today, Reynolds Wrap is made from 8111 alloy aluminum, at the thickest gauge specifications available in the marketplace. Reynolds Wrap® Aluminum Foil is 98.5% aluminum. The balance is primarily iron and silicon. These are added to give the strength and puncture resistance obtained only in the alloy used in Reynolds Wrap® Aluminum Foil.


And Duralumin:

DURALUMIN:(doorăl´yemĬn, dyoo-) , alloy of aluminum (over 90%) with copper (about 4%), magnesium (0.5%-1%), and manganese (less than l%). Before a final heat treatment the alloy is ductile and malleable; after heat treatment a reaction between the aluminum and magnesium produces increased hardness and tensile strength. Because of its lightness and other desirable physical properties, duralumin is widely used in the aircraft industry.

>>> So that seems to rule out waxes, oils, lacquers
Just because you cant smell a trace of such material, instead soaking up the aroma of tomato sauce, or broccoli, or whatever, doesn't mean its not there.

The aluminium foil is made by passing a slab through press rollers and continuously decreasing the thickness of it until the final thickness.  But on the final pass, the sheet of material is doubled, passing two layers through the final press simultaneously, and the shiny side is the roller side, the matte side is where the two sheets were in contact.

Mineral oil is used to lubricate the contact between the foil and presses during production, but most of the oil is 'burned off' as all that heat is released from pressing the metal.  A trace layer MAY remain, perhaps enough to keep it protected evenly?   For the most part, shiny is just due to the press surface, dull due to the other surface being the other aluminum sheet, so any metal oxidation after that should still affect both dull and shiny sides equally, so perhaps the alloy composition used primarily for durability has a side-effect of being more resistant to oxidation over time as well?

grg99, Since you asked about aircraft bodies, I told Duralumin.

The reason for shiny may be..
Galvanizing.. generally done for Iron, (coating of Zn), but may be a similar thing for Al??

Alinimium tarnishes as it forms an almost  invisible layer of aluminium oxide on it but this then protects the rest of the metal from tarnishing, thus it aways seems shiny if it has been polished. The shiny side of  foil (which is dues to the  production process) will in time become very slightly less shiny over time. If you have "aliminium" and it  goes dull then  it is not aluminium but probably an alloy, eg toy cars)

sorry  "aluminum"  not  "aliminium or  alinimium "

aluminium oxide is also known as sapphire.

Also as Alumina ?

So I can give my wife a sapphire ring with a chunk of burnt aluminum?

aluminium oxide has many differnt forms saphirre and rubies being a crystaline one. Carbon also has differnt forms, diamond being one.

You can probably shine it up even better by chewing on it, how about give that a try?

Aluminium is also having a special property.. Once it develops the Al2O3 (Aluminium Oxide) layer, then it will not react with most of the chemicals, including highly concentrated acids. So aluminium is used to store and transport acids in chemical laboratories.

>So aluminium is used to store and transport acids in chemical laboratories.

Must be a rather limited feature, as ordinary ketchup can dissolve aluminum foil, as anyone that has wrapped a meat-loaf in foil can attest to.  Ketchup is a mild acid.

Also spray oven cleaners eat through aluminum foil.  They're composed mostly of lye and lemon-scent I think.

See this webpage (scroll down to the specifications table):

http://www.metalagencies.com/aluminium_houshold_use.htm