O9 And O10 "S" Variety On 243 Ohms Perfin?

I happened upon this 243 OHMS perfin and first thought it was an O10 by looking at the right side "S" when viewing the back. However, there is no Unitrade # for an O10-O243. Then I looked at the left "S" and noticed it to be an "O9". I then scanned at 400 dpi and looked at it full screen and it appears to have both varieties of the "S".

Any thoughts or are my eyes deceiving me, perhaps I've been staring at it too long? I also sent to the BNAPS study group.

Thanks!

Hi Steve123,

This looks like a 'O10' perfin.

Here is the description of the differences between a 'O9' and a 'O10'. Both of yours seem to be vertical and therefor an 'O10'



Here is an 'O9' which clearly shows the 'non-vertical' pin holes.



- stamporator -

Hi, Stamporator:

Thanks for your reply. Yes, I was fooled, I think, by the misalignment of the perfins on the stamp. They both look to be O10. We are using the same chart from Unitrade.

However, based on that, being an O10 perfin, then it is odd that there are no O10-243's listed in Unitrade (2023 or 2024). There is only the O9-O243. Possibly a sheet or several were perforated with the type O9? Or ??? Unfortunately, I am not an expert on the Perforated Official Stamps but noted this one as odd when going through and checking the others that I had.

Steve

Hi Steve123,

The BNAPS Perfin handbook provides the following information for the 'O10' perfin:


As you can see, there are two (2) earlier issues with this perfin (Scott 233 and 235). Both of them have been identified as contrived (ie. possibly done as a favor to someone). The earliest know use of this perfin is July 23, 1946, which is a long time after the Scott 243 was issued (June 15, 1938).

You mentioned earlier that you had sent an email to BNAPS which is good. It may be reviewed and included in future handbooks.

Note: The unbold numbers after the bold Scott numbers in the list is the rotation of orientation of the perfin known for each stamp.

- stamporator -

Thanks for checking the handbook, I didn't on this one. I did send an email to BNAPS, so hopefully it will be added in the future.
Thanks again for your help,
Steve

Stamporator, et al...

The review is in from BNAPS

From Russell Sampson:
The most worrisome aspect of this specimen is the apparent direction the "pins" took in producing the perforations. Unless there is an illusion of lighting occurring here (and that can happen - i.e., the crater vs. dome illusion) then the subtle brightening seen at the bottom rim of many of the perforations indicates that the pins entered the back of stamp - in other words in a direction towards the back of the stamp. To see this refer to the red arrows on the attached magnified and contrast enhanced image. Since the pattern is position 1, then the opposite should be true - there should be "rimming" not "cratering" visible on the back - since the pins would come from the opposite direction and thus push the paper outward as they emerge from the back of the stamp. Entry wounds of perfins look different than exit wounds. Entry wound = crater. Exit wound = rim. The location of the brightening is also consistent with the microscopic shadowing and brightening produced by many flatbed scanner designs as the LED lighting leads the CCD detector.

I've also measured the inter-die distance and if the scan is 400 ppi, then the uncalibrated conversion from four measurements gives 24.73 +0.05-mm which is pretty much spot on for real O8. The perforation diameters are 10 to 11 pixels wide which translates to 0.67-mm +0.05-mm diameters and the nominal pin diameter should be 0.79-mm (i.e., 1/32 of an inch). This difference is about 15%. From my own studies, stacking sheets can produce at about 10% to 15% reduction in hole diameter for stamps nearer the bottom of the stack. So, this appears to be okay too.

To eliminate the possibility of the crater vs. dome illusion, the owner will need to send another scan of the front of the stamp.

after sending 600 dpi of the front and back, the review was:

Tony/Steve: here is Russell's analysis leading him toward the conclusion that the perfin is "contrived'. - faked maybe be too strong a word. A further question - were the images from a phone or from a flatbed scanner? And, feel free to share.

Jim

I used an O10 on Sc 257 (10-cent Parliament) with an Ottawa OC 29 48 cancel. This date and location is in keeping with its expected official usage. Also, the catalogue value of the O10 on Sc 257 is minimal ($0.30 used) and there is nothing special about the perfin (i.e., no doubling, etc.). This all points to it being boring and thus likely to be genuine.

Here is what I did. I overlaid the semi-transparent 1200 ppi copy of my Sc 257 over the Sc 243. As you can see, the match is very good between those perforations furthest apart (i.e., the "H" on the left perfin and the "O" and "M" on the right perfin). This suggests that my registration of the images of the two samples is very good. In other words, the selection of percent magnification and degrees rotation of my sample appear to be as good a match as possible with the perforations of the Sc 243.

Here are the results: There are numerous perforations of the two samples that are more than 1/4 of a perforation diameter different in position. This can be seen as the black and white crescents at each perforation and are marked with yellow arrows. My long-ago results with the O8 block supplied by Gary suggest that to be genuine, die-to-die variations should be less than or equal to about 1/4 perforation diameter, and there were usually only one or two of these per die. Therefore, my result suggests that the perforations may have been produced by something other than the original machine.

The front of the stamp shows some signs of ridging around the perforations - as expected if the perforating device entered the stamp from the back - which given the position of the perfin, is not how a Cummins machine works. However, the shadowing and highlights of these ridges are subtle and so oblique lighting imagery would be necessary to confirm. To see these for yourself, magnify the stamp and look for bright crescent shaped areas around the tops of the perforations, and subtle shadowing on the opposite side.

So far, my vote is for it being a fake, probably done by overlaying a genuine O10 strip over a strip of Sc 243, then using a punch fashioned from 1/32 piano wire to put the holes in the Sc 243.

Also, I am not 100% sure the images provided were done with a flatbed scanner - the file name format appears to be more consistent with a digital camera.




I replied that the images were from a flatbed scanner. If there is any further review after that, I will update. I will also ask if this will be added to the "BNAPS Perfin Handbook" in any new releases.

Steve

Below is a scan of the front (which was never shown in the original post):