Sputnik:
Go to
www.foamfly.com Go towards the bottom of the menu you will see a link "what is fan fold"
Bring it up and you will see pictures of the stuff and a code bar with the product # If you print it off as I understand it they can scan it at Lowes and see if they have the product or use the #s and check inventory. I guess it is not available in some parts of the country. Its primary use (fan fold) is insulation and moisture barrier under alum. and vinyl sidding. You might also be able to obtain it from installers of siding in your area who have it drop shipped directly to them from Dow. Home Depot has a similar product that is pink in color and has the moisture barrier laminated between two thin sheets of foam. I havent used the pink yet but is said to be a touch heavier and more brittle than blue. But they say it paints better with craft paints so kind-of a trade off I guess.
Good Luck in your search
Bob