Quick Question On Canada Postage Due

Was sorting a lot containing a bunch of Canadian postage dues to put into my album when I came across these two 5 cent issues. It's my understanding that these only exist in two perf varieties - 12 by 12 and 12 1/2 by 12. However, these two have perf 13 by 12 - triple checked them. I didn't see any reference to this variety in either Scott or Unitrade.

Any Canadian experts out there who would be able to shed any light on this?

Thanks in advance

The stamp on the left has two perfs that are very close together, above the middle 'A'. Wouldn't that foul up your reading? I see it at the bottom which makes me think it really is a freak of some kind.

Yes, but those two close perfs have a wider than normal Gap to the next left perf hole. (The same also applies to a lesser degree on the right hand stamp.) Also, both stamps have 14 holes horizontally, ignoring the corner holes. If they have different perfs, then one should be wider than the other.

Could you provide a scan with the stamps one above the other and the perfs touching?

I believe these are perforated with an "H" shaped comb perforation like this:


Any slight mis-advancement of the paper will result in wide or narrow central perforation bridges.

Here is an image (borrowed from ebay) in which the central comb punch is shifted slightly higher than the partial punch to the left and right.


Thus gauging the top/bottom perforations, one has to do either the left half or right half, but not spanning the center "joint"

Here is an old thread where the H shaped comb perf is
discussedhttps://goscf.com/t/65546&whichpage=8

Did my best to physically line up the two stamps every which way.

Thanks, OofD. They do look like the same gauge. It's just that the stamp with the higher perf measurement has had that one - inter-H? - perf gap foreshortened,

I had a similar difference with Scott 1288 UN International Literacy Year.
When I mentioned this to Robin Harris, editor of the Unitrade catalogue, he answered:

"There was only 1 perforation used on this stamp. The discrepancy comes from how the stamps were perforated. The H-comb perforator may not align exactly right all of the time; some times it may leave a narrower or a wider perf in the middle of the horizontal row. This can cause an apparent perforation difference on certain specimens.
The only way the stamp could have a different perforation is if it had one more or one less perf hole across the stamp. If that was the case, the perf would either be 12.7 or 14 instead of 13.3."

Note the perf gauges he mentioned pertain to Scott 1288, not your postage due stamps.

Hope that helps.

Peter

Thank you all for your comments. I appreciate your input with respect to this little mystery.