While going though my father's US album and entering it into EZ Stamp I came across the two stamps attached. Am I missing something or is 613 Perf. 11 the real deal? I have very limited measuring resources but both appear to be 22 1/2 MM in height.
Thanks Jack - no I am not sure, that is partly the reason for putting it out here for the experts to take a look at. I tried measuring but do not have anything that is really accurate. It does appear to be 22 1/2 MM. How do I tell if rotary other than measuring?
Since you have both stamps in the same scan, use a mm ruler to measure the height of these on your screen. Doing so you should find that the left (perf 10) stamp is taller than the right (perf 11) stamp. Which makes the stamp on the right probably Scott 610 (Flat Plate). The one on the left is most likely correctly identified as Scott 612 (Rotary Press). Note that the height difference is accentuated by the enlarged stamp images on your display. Which makes measuring that difference much easier. Added: You might check the back side of the perf 11 for "setoff" ... during the printing process, flat plate sheets would often be stacked for drying and some ink from the sheet below would adhere to the back side of the sheet above it. Absence of setoff would not preclude a stamp from being a flat plate issue, but presence of setoff would pretty much clinch that it is flat plate (i.e., 610).
Great idea on measuring the screen as enlarged. R stamp measures (enlarged) 23.8CM vs. 24.2 for the left. Guess my Dad had it mounted incorrectly. Does not happen very often. Guess that also means I need to keep paying off that loan the slow way. Thanks all for the input.