Hoping you are using the "one side round and one side flat" rolling mat, and not the cheap kind with both sides round. Cover the rolling mat with a plastic wrap starting with the round side, and ending with it. Make about 2-3 full rounds of wrapping. After you are done wrapping, roll the mat to squeeze out all the air locked inside the wrapping. If needed - poke it with a toothpick to let the air out.