Measure the physical stamp
Measure outside edge to outside edge in millimeters, including perforation tips.
Free storage sizing tool
Find the right mount size for your postage stamp
Upload a stamp photo and optionally enter its measured width and height. Get practical inner dimensions, fit checks, and safer material guidance.
Drop a stamp photo here
Show the full stamp, every perforation, and as much front detail as possible in even light.
How much larger should a stamp mount be than the stamp?
A stamp mount should have enough internal clearance for the stamp to sit flat without pressure on the perforations, but not so much room that it slides around. Measure the physical stamp across its outer perforation tips and compare those dimensions with the mount maker’s stated inside size.
A normal photo does not provide a reliable physical scale unless a known measurement is included. Entering measured width and height produces the safest recommendation. Material also matters: use archival products clearly identified as acid-free and PVC-free.
How it works
Choose a mount that protects without squeezing
Mount sizing uses the physical stamp dimensions, not the dimensions of an old sleeve or the pixel size of a photo.
Allow modest clearance
The inside should be slightly larger so the stamp does not buckle, rub, or catch at the corners.
Check the material
Prefer clearly identified acid-free, PVC-free polyester, polypropylene, or polyethylene products.
How to choose a safer mount, strip, or album pocket
Correct sizing protects the perforations and paper while allowing the stamp to be inserted and removed without force.
Measure the stamp itself
Measure in millimeters from the outermost perforation tip on one side to the outermost tip on the other, not the dimensions of an old sleeve.
- Width and height measured separately
- Flat stamp with no curled edges
- Outside perforation tips included
Check the inside dimensions
Product listings may quote strip height, outside size, or usable inside space. Confirm which measurement is shown before ordering.
- Small clearance on every side
- No pressure on teeth or corners
- Enough control to prevent excessive movement
Choose stable materials
Avoid vague “plastic” descriptions. Look for products intended for long-term philatelic storage and follow the maker’s handling instructions.
- Acid-free and PVC-free specification
- Polyester, polypropylene, or polyethylene
- Clean album page and dry storage environment
Continue your research
More stamp guides and free tools
Explore another collector guide or use a free tool to check the next detail on your stamp.
Common questions