Home made bare metal foil

Maybe you are refering to this Ultra Thin Doubled Sided tape material. 

http://www.chipsetsupplier.com/htm/130/129-130-409-80mmx55%20meters%20Ultra%20Thin%203M%20467MP%20Double%20Sided%20Tape%20Sticky,%20for%20Plastic,%20Rubber,%20Metal%20Adhesive.htm

For brick and mortar shopping, look into electronic supply shops, autobody shops, and maybe stationary shops.

If you are referring to the old time waxed paper they used to wrap brown bag sandwiches in before zip-locks, try the local grocery store back in the foil wrap section.

You could just use the thinner grades of aluminum foil, too.  It's usually the cheaper grade than the thicker aluminum foil.  I think there are a couple of builds in the Aircraft forum that illustrate using kitchen foil, with white glue as the adhesive.  I remember a build of Monogram's B-29 kit, using kitchen foil.

Also, here is a thread at the ARC forum, demostrating using kitchen foil and Micro Scale foil adhesive:

http://www.arcair.com/tnt1/101-200/tnt137-BMF-Popojan/00.shtm

OK, and here is the B-29 build I was thinking of, it's also at ARC:

http://www.arcair.com/Gal5/4601-4700/gal4687-B-29-Shred/00.shtm

I will try this myself, some day, just haven't gotten around yet to queuing up an NMF subject in my modeling queue.

Hope those articles help!

Best regards,

Brad