The world's #1 stock sheet for over 25 years! Every stamp mounted in a Hagner Stock Page is firmly trapped between two inert substances. The highest quality, ph neutralized, paperboard and crystal clear, PVC-free, polyester film have been so strongly joined together that more than 50 overlapping stamps will stay firmly in place under a single strip! No PVC, No Acetate, No polystyrene, No plasticizers, No sticky adhesives!