In Brisbane the place to go is Insulation Supplies, 330 Curtin Ave (west) Eagle Farm. 07 3268 7399. They are specialists in insulating materials. I'm sure there will be an equivalent place in all the cities. They also have 10mm foam sheet with aluminium facing one side, self adhesive the other, I used a double lthickness of this to make my cold air box and it is very very effective.