This is true of Duragilt, but not Permadent. Permadent starts with a pronounced, raised, cell impression that is wax coated. I have scraped a bad comb off on several occassions after 3 years of using Permadent and the bees always will rebuild. After the bees chew off the wax coating on Duragilt all that is left is a smooth sheet of plastic. Permadent is also less labor intense to install than Duragilt as it is a rigid sheet that just snaps in the frames without the fear of damaging it.