A perforation gauge.
perforation gauge (plural perforation gauges)
- (philately) A device for measuring the number of perforations per 2 centimetre distance along the edge of a postage stamp.
1872, The Stamp-collector's magazine, volume 10, page 110:
- The perforation-gauge is surrounded by a neat border, and inscription indicating the price — one shilling — and the publisher's address.
2001, The American Philatelist, volume 115, page 686:
- We desperately need starter materials such as stamps, albums, perforation gauges, hinges or mounts, and magnifying glasses — any materials that a novice collector requires to get started.
2014, Adam Gregory Koch, Philatelic Philosophy: Stamp Collecting Wisdom & Opportunity:
- It is far easier to use a perforation gauge which for a few dollars can be found on eBay.
device for measuring perforation