Perforation Rarities...

I have been looking at some of the perforation rarities and cannot find any information on how the perforated 10 at top or bottom stamps came about?? was only one row perforated 10 and rest 11? Is it possible to have 10 at top and bottom with 11 on sides? So far the only reference I can find on this is the link below which shows each rarity but not how they came about. Any and all information is much appreciated. Thank you.
http://www.siegelauctions.com/2010/...Sale1001.pdf

The cause of these perf errors varies. The compound perf 10X12 and 12X10 (Scott 423A-F) were produced during the transition from perf 12 to perf 10. The perfs were applied by running the sheets through 2 perf machines, one did the horizontal perf and one did the vertical perf. During the transition some machines were setup for for the new perf 10 while others were still set for the perf 12. These sheets were ran through perf 12 on one machine and perf 10 on another.

The perf 11 third and fourth Bureau printings (and one occurance on postage due) with perf 10 on one side were produced when a perf wheel was repaired and the wrong pins were installed. The perf 10 is always on the short side and the error occured on 2-5/8 stamps.

The coil waste issues were 2 types. The first were the perf 11X10 (Scott 538, 539, 540, 541, 578 and 579) were produced from rotary press coil web remnants that were too short to use for coil rolls of 500. The was cut on the jointline into sheets of 170 (10X17). The web had already been perfed 10 vertically (for the cols) and were ran through the flat plate perf 11 perforator in the horizontal direction. This was done to make these remnants usable for postal sales.

The second type of coil waste is the perf 11X11 (Scott 545, 546, 594 and 595). This was from rotary press printed web that was removed prior to the perf operation. Once again the web was cut on the jointlines into sheets of 170 and ran through the flat plate perf 11 perforator in both directions.

The sheet waste issues perf 11X11 (Scott 544 and 596) were rotary press sheet stamp web that had been removed prior to the perf operation. The web was cut into sheets of 400 and then split into half sheets of 200. They were then ran through the flat plate perf 11 perforator in both directions.

It is generally believed that Scott 613 was produced as sheet waste.

Hope this helps

Thank you Russ for your extensive response. I guess my question pertains to the Perf 11 third and fourth bureau printings(specifically something like a Scott 516a 30c orange red Franklin perf 11 (10 at top or bottom)). A question in regards to the perf 10 being always on the short side(of the sheet or stamp??) and the error occurred on 2-5/8 stamps? meaning? what is 2-5/8? Again, thank you.

Ok, so I guess I found 2 diagrams that help me visualize it better. So is what I put in the second diagram correct? That if one of those wheels were replaced, then that was when the perf 10 wheel was accidentally put in? Still not getting - "The perf 10 is always on the short side and the error occurred on 2-5/8 stamps."

Jcstamp, there were 28 pins involved in this error. As a result the lenght of perf 10 equaled the length of 2-5/8 stamps. This resulted in a transitional stamp having both perf 10 and perf 11 on the same edge.


The image above is a transitional on the bottom with the last 3 perfs on the right being perf 11.

Ah, ok....thank you very much for explaining that.