How Much Size Variance Is Normal In Washington-Franklin Perforations?

Really stepping outside my knowledge zone on this one.

I encountered this cover, which I thought might be an FDC as it was in with a bunch of other FDCs, but the date doesn't appear to match any issue date in Scott: September 25, 1923.

I then looked closer and noticed the difference in horizontal vs. vertical perf spacing, so I broke out my old trusty metal multi-gauge... but the perfs don't exactly match up.

I then broke out my "Precision U.S. Specialty Multi-Gauge" that I bought from Stanley Piller a number of years ago at Chicagopex, great for measuring perfs on cover.

By my calculations, the block measures 9.7 x 10.8. Rounding up to 10 x 11, I believe that makes the block Scott #542.

Is that a correct assessment due to paper shrinkage, or does the variance from the norm make this something different?




It's a sealed envelope with no contents, which implies that it was philatelic. Interestingly enough, the addressee was a postal employee:

https://e12fdc.wordpress.com/streich/

You need to use the dot scale elsewhere on the gauge to measure US perfs. The line scale and standard perf gauge is based on millimeters whereas US stamps were originally perfed based on inches. The dots on that scale are made to also correspond to the actual perf hole sizes used. The US gauge should be essentially dead on.

Got it. Using the center section, they gauge exactly 10 - 81 x 11 - 72.5. Not sure what those secondary numbers mean.

Rev, here is a great article explaining the Kiusalas scale: http://www.usca.nl/wp-content/uploa...SA-Gauge.pdf


Peter

Scott 542 10x11 (10-81x11-72.5 on the Kiusalas scale) is correct. one more day on the cancel would have been three years to the day past the EDU. If you should decide to part with it, send me an e-mail.

Use of the Kiusalas scale to identify and authenticate Washington Franklins was the subject of Ken Martin, "Adventures in Expertising" in The American Philatelist, Jan. 2021, (pp.66-7). Pretty lucid explanation with a nice chart and some illustrations.


edited to add page numbers

The original Kiusalas gauge does not have 11-72.5 which makes this reading 11-725 in ten-thousandths of an inch rather than thousandths of an inch. It does have 11-73 on it of which 11-72.5 is more accurate for it.