Perforation Anomaly On US Scott 2728 - What Is This?

So, I have several lower left plate blocks of 6 from the 1993 American Music series; Scott 2724-2730. Stamps in this issue have 15 perforation holes, vertically. Except, the left (margin) side of #2728 has 14 holes... and the difference is quite visible: the perf holes near the center of the stamp are clearly too far apart.

Technically speaking, that would make the stamp "irregularly perf 10 at left."

Possible explanation: A pin broke during a production run. Rather than a long shutdown of the machine to replace a wheel, some "enterprising" individual took it upon themselves to BEND the 4 adjacent pins to compensate and restarted the equipment to run "sort of OK" until end-of-day shutdown. Perhaps it was already near the end? I say that, not really knowing much about modern US production equipment, and what is possible.

I have looked a dozens (maybe 100s?) of full sheets and plate blocks of these, as well as 100's of individual copies of #2728, and have not otherwise come across this.

Origin: Came from Austin, Texas... I was working for a retail store, and we were mailing out a few thousand invitations to an event, and decided to hand affix these particular stamps to them. So the 3 blocks I have came out of a stack of maybe 80 sheets purchased at the same time. These just happened to be the ones I saw, so I don't know whether ALL those sheets were the same.

I've collected stamps for 50+ years (although not US), and have only seen things like this - very rarely - on a few foreign stamps from the 1800s, and even then it's usually just bent pins from impacts with rocks in the paper pulp.

Any comments, feedback, observations, wisdom and whatever else would be welcome!

Absolutely intriguing! And feeling in a speculative mood to muse a bit...



Observations, here is an image of a full (normal) pane borrowed from the internet:

Note the perfect intersecting lines of perforations, the perforating of the upper title block not running off the edge of the pane, nor off the bottom, etc. It seems logical to me that the perforations were punched in a one-stroke operation, rather than a traditional set of rotary perforating wheels running twice across each pane at a 90 degree angle.

Second, I manipulated the original image and placed two copies of the stamp in question next to each other to emphasize the fascinating anomaly:


I do not know how many panes were on a press sheet, but strongly suspect this occurred on only one pane of the 8 or 9 or 12 or (?) panes in the press sheet. Unfortunately, this issue does not contain the plate position diagram. The scarcity makes one wonder whether this was present from the beginning or was progressive damage/repair during production?

The pin wheel needs a counterpart to correctly work. You can't just bend pins "to fill a gap" as there is no counterpart to "grab the bent pin(s)". The bent pins would instantly break, or at least form irrgeular holes. However, your strange holes are perfectly round.

My guess this is a production error of the pin wheel/counterwheel. Whatever the cause of this error may be, it went unnoticed until you detected it.

Perforators with pin and hole wheels make line perforations which cross each other unevenly at the stamp corners.

I believe this issue was skivved, not perforated.

eyeonwall,
Your statement confuses "ends" and "means" Clearly the stamp is perforated (the end) in the sense of a separation method, but you suggest it was done by a means other than perforating. Please explain in detail as your terminology will mean absolutely nothing to the vast majority of the readers here. Additionally, how it would happen to only some panes.

Skiving pushes on one side of the pane with cones and the raised areas are shaved off (knife instead of receptacle). The cone pattern had to be off. Perhaps they noticed it was off and they replaced them with a proper set.

Could we have a scan of the back of the area in question? I'd like to see if there are some "albino" punched areas.

I thought skiving was/is used by SSP (Sennet Security Printers) for their coils.
If this sheet issue also used skiving instead of a comb perforator, it could explain it as eyeonwall suggests.

Thank you for all the input and replies, I appreciate it!

I was going to post a scan of the back, but then my scanner went AWOL, thanks to a software update. Fixed now, here's the back:



It's a surprisingly eyecatching thing, once seen next to the normal; thanks John Becker for graphics magic!

Regardless, it would seem the "problem" was fixed very quickly; I've been (actively) looking for other examples since the time the stamps were issued, but never found any.

Do we actually have any evidence of the pin chronology? I don't think so.
Was it always that way on that pane position?
How many panes were perforated with each machine cycle?
What is the press-sheet size?

I doubt these were perforated by a skiving process. Can anyone supply PROOF of the perforation method. They look cleanly-punched to me.

Has anyone found a literature reference to this variety? I did not see anything in "The Specialist" in the few years following the issuance, which is where I would expect it to be reported. This thread may be the discovery moment!

When this thread started, I was able to find two panes containing the perforation variety on ebay (and bought them. Awaiting their arrival.)

Regardless of the back-story, I see this as a catalog-listable variety at a modest premium.

It'll be interesting to see what else comes up. I was somewhat surprised there was no mention of this anywhere... even after 30-odd years. Especially since you were able to pick up two sheets on ebay... so they are out there, in some lesser or greater number.

I would be inclined to suggest that they are at least "mention worthy" in Scott US Specialized.

Cool !!

The perfs on right side also seem slightly out of alignment.

.

Both panes have now been received from two different sellers matching the OP's example. They show the same constant perforation variety to the Otis Redding stamp in position 26:


Now with full panes available, also noted above is position 18, the middle stamp in the middle column and row, featuring Ritchie Valens which exhibits (what I will describe as) a split perforation pin under the "S" of Valens. Identical on both panes with no evidence of indentations to have a blind half perf.


To expand on the perforating quality of this issue, I also found two examples of another pane showing perforation anomalies, the lower left portion of a pane is shown:

Note the LL corner stamp showing a split perforation pin:

And what appears to be two missing pins in the central block, but both of these positions show circular indentations, thus only "blind perforations":


I agree with thinkstamp's observation (and expand on it) that there are several minor pin misalignments on each pane.

Upon further mulling over the Scott catalog and the panes for sale, most plate layouts of this era seem to have only 4 or 6 panes in the press sheet, thus if seems these examples show a progressive condition not on all panes from a particular position for the full production run or they would be much more common in the marketplace than about 1 in 30 or so of the recent panes surveyed for sale.