Polypropylene is characterized by its high transparency, gloss, and is stronger than polyethylene. This packaging material is suitable for use in stationery as well as for displaying clothing, miscellaneous goods, books, documents, and other promotions such as DM posting. Packaging Land OPP bags are domestically produced. Precautions for Use: Do not place near fire. Do not use in microwave or oven. Please be aware that if you put a sharp object in it, it may tear. Please do not put any liquid.