Scott 37 - Compound Perforation?

Good morning

I understand that with pin sharpening, there are possibilities of compound perforations for older stamps. When you really think about it, compound perfs should almost be expected...

Here is an example which is 11.75 on top and bottom, 11.8 on left and 12.0 on right. Is this an anomaly?

Are compound perfs a recognized aspect of SQ collecting, or just considered an oddity?

Chris

To me it looks like 12 left and 12 right side..Just my opinion.
Robert

Hi Robert - thanks

It might be an optical illusion, but I still don't see an alignment. When I place the stamp next to another P12, it doesn't match. GIMP shows a measurement difference, and the trusty gauge shows a definite difference.

Thanks for the image - on the far right, the perf aligns, but on the far left (the full perf, not the rounded), they don't match.

Oh well, I'll place it in the 'to be studied' for a rainy day...

Chris

wert's comparison appears to me to show that they align at the right side (tops of the stamps), but definitely mis-aligned at the left side.

I'm not aware of any compound perfs, so suggest that its an oddity possibly caused by stretching or shrinking after printing.

Hi Blackjag - thanks for the thoughts. Yes, an oddity, but the image is exactly the same top to bottom on each side, so paper deformation after the print would change the size of the image, as well...

Chris

Assuming Lars714's and wert's images are accurate interpretations of the two stamps, the top stamp is smaller than the bottom stamp evidenced by the two angled pink lines at the right.

I erroneously added two blue lines, which are now removed from this re-posted image.

As these were line perforated, with rare exceptions you don't see complex perfs too often.

It is best to align the bottom of perf holes, not the perf tips. Looks to me Wert is correct and that the perfs align fairly well.

You'll see a lot of bent and missing perf pins in this era, you can't just measure between points and expect accuracy; one must allow for error in gauging a perforation.

Right side perfs digitally compared to left side perfs



Don

It is rare that a person has scanned the stamp perfectly straight. So the first step whenever you do anything to a digital image is to check for 'straightness'. Lar's original image is titled to the left by 1/2 degree.
Here is his image showing the 1/2 degree tilt to the left (red area) and the image straightened. Note the interior bounding box now shows the stamp design straight.


Now with the stamp straight, we can use a bounding box to determine how square the perfs are, the bounding box below shows the perfs are straight and parallel.


In my opinion the left and right perfs match, all the perfs align squarely and are normal.
Don

to all - a BIG thank you for taking the time to analyze this stamp! Appreciate you for attempting to sort this out. I will make extra sure in the future to maintain a complete alignment on scans.

The hand held measurement still shows a difference (11.8 and 12.0), but the digital seems to show an equality on the two sides. A learning experience?

Chris

Sometimes you eyes can play tricks with your mind.

Ever see the moon in the sky (typically when it is close to the horizon) and it looks huge? The moon does not change size, it is just your eyes messing with your brain. The moon is always the size of an aspirin held between your thumb and finger at arms length. If you hold an aspirin up to one of the 'large' moons it will instantly 'shrink' back to the normal size.

Here is another simple example, the gray bar below is all the same color across its width. But your eyes see it as a gradient, tricking your mind.


Don

Love that example Don..
Exact same colour.
Robert