How to Choose Mounts

Mounts are sold according to size in millimeters. The first number is the horizontal measurement, or width, across the mount. The second number is the vertical measurement, or height, of the mount. Example: A 45 x 30 mount measures 45 mm wide by 30 mm high.

The Most Common Mount Sizes

The most commonly sized US stamps are pictured on this page along with their mounts. To find the mount size you need, place your water-activated stamp over the illustration that fits exactly.

For stamp sizes different from those shown (including self-adhesives) find what you need on our website: Enter the Scott number and you’ll see the correct mount size.

If you don’t know the Scott number, you may enter the measurement of your stamp in millimeters – width first, then height. If your stamp falls between two sizes, select the larger mount. Sizes for water-activated stamps are generally 5 mm larger than the stamp in both directions. See how to measure your stamps at

Please Note: The mount size for self-adhesive stamps is generally 6-7mm larger in each direction because their backing makes them thicker.

If your stamp needs a size that doesn’t fit the guidelines, our online mount finder will give you the size most closely matching your stamp. This happens when the stamp measurement has been rounded up for a more generous fit.

Still need help choosing mounts? Call Mystic and tell a friendly Customer Service representative who will gladly help you.

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