I am going to be selling cakes in a local store, but I first have to have proper packaging. I dont want my packaging to be "cake wrapped on plastic wrap on the counter). I am investing in professional packaging like "Hostess". I looked at some heating/sealing products but isnt there some "air" in the Hostess packaging before you open it? What is that? Do I need to inject something into the package first. What preserves it? HELP... I can't find the info online.