US 1 Cent Washington Perf 12 X 12 X 11.5 X 11.5 ?

I was cataloging this postcard for my Minnesota Postal History collection. I thought I would measure the perfs to perhaps identify the stamp.

I have measured and re-measured.

Best as I can tell this stamp is perf:

12 at top
12 at right
11.5 at bottom
11.5 at left



Is this possible or am I imagining things?

It looks like the top perfs match the bottom perfs.

No. Measuring perforations on US stamps with a metric perforation gauge frequently results in errors. Find an unambiguously perf 12 stamp like a commemorative of the period and carefully align the perforations on all four sides to check alignment starting at one end. The perforations are likely to match on both ends. A 10 or 15 power loupe will also be helpful.

It is also possible to use a transparent Multi-gauge that replicates the Kiusalas gauge. US perf 12 hole spacing is 0.066 of an inch, sometimes referred to as 12-66.

Clark

Thanks Clark. Excellent advice. I do have the multi-gage, and it matches 12-66 gauge perfectly.

Antonio