They have an adhesive strip on the bag instead of flap, so your photo cannot come in contact with the adhesive.  These 1.6mil clear photo bags made from "Biaxially Oriented Polypropylene" (BOPP).  BOPP is a durable plastic designed to limit ripping, tearing, wrinkling, or fogging. They contain 10% recycled polypropylene.  Close and reclose these bags over and over.