Clear "Cello" style bags provide a nice, professional presentation and finish. Made of high clarity polypropylene film (OPP). Different than soft polyethylene like zip lock or sandwich bags. These bags a crinkly. Not porous, they don't stretch, and are more rigid. Polypropylene is a material approved for food packaging. Keep your cookies and bakery items fresh. Perfect treat bags for birthday party, baby shower, bridal shower, or tea party. Great for packaging candles, photos, art, soap, jewelry, crafts and gifts. These are resealable cello style bags with a peel off strip that reveals a sticky band. Fold over the longer flap on the bag to close. Bag seal can be reopened.