A heavier aluminum foil has been discussed several times here.The opinion is that heavy duty foil is what the standard foil used to be.It is a matter of manufacturers trying to maintain a production cost and market pricepoint balance.The best you can do is find some new old stock from Grandmas pantry.You may try foil from comercial kitchens.It may be thicker but I doubt it.Comes from same mills(ALCOA) and are just longer rolls.

BOATMAN
John