180 Gram Record Jacket Sleeve 13 x 13" 1.5 mil POLYPROPYLENE 1-1/2" Resealable flap Reseal tape is located on the body of the bag.Polypropylene (PP) is a crystal-clear, high sheen, crisp material. We use bi-oriented polypro which means that when the material is made, it is stretched in both directions so that in time it will not "pucker" (decreasing the clarity). It has been tested by an independent lab and confirmed as safe for long-term storage. This material does not contain PFAS chemicals (forever chemicals). The recycling symbol #5 indicates that these sleeves may be recycled at some retail and grocery stores.