Check the listing for details. Showgard Stamp Mount Strips: 25mm - Black. Condition: New. Listed at 12.64 USD. Showgard Stamp Mounts are made from archival, plasticizer-free oriented polystyrene. They contain no softening agents or other components that might be harmful to postage stamp ink, paper, or gum. Showgard Stamp Mounts do not shrink or discolor and are 100% waterproof. The components used in Showgard Stamp Mounts have had philatelic application for more than 40 years in every climate of the world and proven perfectly safe for stamps. Showgard mounts have a very functional design using twin parallel welds to keep stamps securely in position while permitting free passage of air around the stamps. These uncut mount strips can be cut to the desired length. Showgard Stamp Mounts are the most popular, most widely used and most respected stamp mount in the United States market. Backing Colors Available: Black or Clear Height: 25mm Length: 215mm Common Uses for This Size: US Commem and Regular Issues Number of Stamp Mounts per Pack: 22