The Showgard 40x25mm (Size J) in Clear is the transparent version of the most widely used mount for Horizontal U.S. Commemorative Singles. These pre-cut mounts are entirely transparent (both front and back), providing a "borderless" look that allows the stamp to blend into the album page or permits the collector to view the reverse of the stamp without removing it from the mount.
Size J Designation: Specifically sized for the standard "Junior" or standard-format horizontal commemoratives issued by the USPS (roughly from the 1930s to the present).
Maximum Transparency: Because both the front and back are clear, these are ideal for stamps where the gum condition, watermarks, or expertizing marks on the back are of particular interest.
Archival Grade Material: Made from 100% oriented polystyrene, which is free of plasticizers, acid, and harmful chemicals. It is 100% waterproof and will not shrink, stiffen, or yellow over time.
Twin-Weld Design: Features Showgard's signature parallel welds at the top and bottom. This creates a secure pocket that allows air to flow around the stamp, preventing "toning" or moisture traps.
Split-Back Opening: The clear backing is split horizontally. Gently flexing the mount opens the split, allowing for safe, easy insertion of the stamp without the need for tweezers to touch the delicate face.
| Feature | Specification |
| Size Designation | Size J (40/25) |
| Dimensions | 40mm Wide x 25mm High |
| Orientation | Horizontal (Landscape) |
| Color | Clear (Transparent Front and Back) |
| Quantity per Pack | 40 Mounts |
| Primary Use | Standard U.S. Horizontal Commemoratives |
This size fits the vast majority of standard rectangular U.S. commemoratives, such as:
The "Famous Americans" Series (1940): (Specifically the horizontal issues).
Statehood Anniversary Stamps: The standard 3¢, 4¢, and 5¢ commemoratives.
Modern Commemoratives: Most standard-sized horizontal stamps from the late 20th century.
International Issues: Widely used for horizontal commemorative singles from Canada, the United Kingdom, and Germany.
Visual Integration: If you are using colored or highly detailed custom album pages, clear mounts don't interrupt the background design with a black block.
Verification: Ideal for high-value stamps where the collector may want to verify the "Never Hinged" (NH) status or look for "Secret Marks" on the reverse side.
Because there is no black background to hide errors, placement is key. Use a Showgard Mounting Mat or a simple grid guide to ensure the mount is perfectly level. When moistening the gummed back, use the smallest amount of water possible; since the mount is clear, any "squashed" water droplets or excessive moisture trapped behind the mount will be visible.