Why are the perforation holes different on the same side?

[Historama.com]

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On this vertical pair of Mandate 20m stamps, if you look at the shared horizontal perforation you'll notice certain holes are larger than others, particularly towards the right side - but there is no pattern.

If this is supposed to be 13.25 gauge, why would the hole sizes vary? I thought the holes remain the same size throughout the perforation -?

...as usual, my upright images are appearing here horizontally...

Alex

[Global Administrator]

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Replaced perf pins here and there most likely.

Slightly different gauge.

[Historama.com]

Thank you!
It’s been driving me crazy: various sources give 13.25 or 13.5 as the gauge - and the truth is, neither really matches. Now I know why...

[Global Administrator]

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"Knowledge Is Power"

This kind of thing was absolutely normal looking on many printings from Victoria, circa 1900. Uneven and ugly looking perfs were often the norm there.

Depending on the gauge, you get sharp pointed tips and blunter ones, but as we can see both were often badly aligned, even on 1 side.

Victoria of course printed the WA stamps in this era, and similar ugly perf spacing is VERY normal -

This above too probably looks to the untrained observer like an "amateur reperf" but it also is 100% perfectly genuine.

You can even see large and small perf pins in use along 1 side of each stamp of this WA block 4!

Glen

[pelmen]

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My take is that the pair in question was weakened at the post office and when affixed to the envelope were lined up. The "large" holes are oblong, not round as Glen's fantasy would create.

Likewise at the left end of that row the holes are smaller and have marks across the middle of the paper joins.

I would guess if you gently felt those you will notice a "lumping" where the paper is doubled over and if you soaked them I would expect them to separate.

Was that issue as a single the typical postage rate at the time? The stamp may have been folded to prepare to separate from the source sheet, weakening it.

If you hold up to light I would also expect the attached paper between the large holes to be lighter than the surrounding paper and at the left end of that row to be darker.
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