When ordinary cling film to wraps white mushrooms, the white mushrooms in contact with the plastic wrap will turn yellow quickly, so compared with ordinary cling film, PE Micro-Perforated Film can keep white mushrooms from yellowing in about three days, and the fresh-keeping period can reach seven days. Air permeability: fresh vegetables and fruits need to exchange oxygen, carbon dioxide and water vapor, because of proper air permeability, the preservation period of food can be prolonged.