Rolls Log

what kind of cardboard is used for the tray under the big tootsie roll logs, and where can I buy it in sheets?

is it wax? silicone? just plain old posterboard?

http://www.google.com/search?num=50&hl=en&safe=off&q=food+grade+coated+cardboard&aq=f&aqi=&aql=f&oq=

Chili rolls log