My new Precision U.S. Specialty Multi-Gauge has a perforation gauge for Bureau Issues. There are multiple sizes for some of the perforations . An example is 10-81, 10-80 , 10-79. Perforations 11 and 12 also have multiple numbers
What does the second number indicate and can it be used to differentiate stamps?
Hi Larry, I recently wondered the same thing. Click the link below to see a lot of info. The short answer is that the second number is the distance between the holes, or pin spacing in thousands of an in.
