Imperforate Coil Waste Stamps

Hi

I am trying to gain a better understanding of Schermack Coils. I've noticed that on many stamps the holes don't appear between stamps but on the stamp itself. The stamps are perforated by the Companies before being placed into the vending machines. The machines then cut the stamps at the time of sale. As I understand this subject the companies were having difficulty with the perfs because some stamp sheets had spacing that varied between stamps as on the example of Scott 383 below. This block of 16 has more space between rows 1 and 2, and 2 and 3. The remaining rows have only 2mm spacing between them. Would it be accurate to say that misplaced perfs were the result of perforating stamps from sheets that had varying degrees of spacing between stamps?

*bump*

There are so many that are badly centered out of what I've seen that it seems that centering was not a major concern. Note how paste ups were often fairly crookedly aligned, so there was no attempt at care there. Or was that the PO's doing? If centering was a concern, one would think that uniform stamp-to-stamp spacing on the printing plate would be a concern.

Lack of care in centering also seems to be par for the course for PO-perfed stamps back then. Today, we are looking at mint examples that are generally better than average, having been mostly selected by collectors. And compare what we see for private perf mint stamps vs. used ones and ones on covers. I think the larger population of used private perfs shows just how badly centered the average private perf could be, trimming by applicator notwithstanding.

hy-brasil

Thank you for your response. I have to agree that lack of quality control was likely the dominant cause of poorly centered perfs. I hadn't considered that initially. I was looking for a technical cause instead and this blinded me to other possibilities. The example below is typical of a poorly centered perf.




I'm sure more extreme examples exist.

It's a frustrating issue I see with US banknotes too. Here are two twenty dollar bills from my wallet. Notice the inconsistent vertical centering: