Construction
Rows of holes are punched between stamps so they can be separated while leaving a toothed edge.
Type study · separation
Perforated stamp
Punched holes turn the sheet edge into an engineered tear line—and can become an identification measurement.
Measure, don’t eyeball
The National Postal Museum identifies the perforation gauge as a tool for distinguishing stamps that otherwise appear similar.
Evidence: npm-tools
Condition vs identity
Missing teeth can affect the surviving object, but the first task is to identify the issue correctly before making any condition judgment. This universe does not provide market grading or value estimates.