Correct Perferations

I'm going nuts... As a former collector, I had a lot of trouble measuring perferations. I recently took the hobby back up and am still having trouble with perferations.
Every 2 cent Washington seems to be a 12.

A little help via pictures would be great on where exactly and how.

I find it hard to believe that all 200 Washington reds I've checked are only 12x12 perfs. Some seem closer to 11 1/2 or 121/2

Msaine, are you using a perforation gauge?

Peter

Yes... A clear use gauge. It has both the dots and the dots with lines

My best guess (logically) from what he's stating is... that
very possibly all of the stamps he's checking are perf 12's...
most certainly (not) out of the realm of possibility...

pics would most certainly help...

200 406's perhaps ??? (assuming 2cents2)

TWOCENTS of course opens other possibilities...

Unfortunately, some gauges out there are inaccurate which can cause errors in measurement readings. Sometimes I use a set of stamps that have different known perforations on them that allows me to compare other stamps against them. Check the following out: https://goscf.com/t/37904

I've personally used a variety of perf gauges,
and haven't to date ever had one that did not
accurately measure any perf...

My old MEGHRIG metal one has served me for years...

Perhaps find one stamp that you are sure of the measurements of (measure how many perfs within 2 centimeters) and then use that one as a guage to match other stamps up against, setting them side by side to compare

I only collect US... pretty cut and dry...
8,10,11 and 12 for the most part, with a
few exceptions... so, if (any stamp) is
off by a decimal point, it's would not
be significant enough (for me) to become
a purist to find out why or get a more
exacting measurement... for me, it would
be a superfluous undertaking...

Questions
How to check a perferation gauge
Do you round up or down
Does anyone have accurate pictures oh what it should look like