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This is a brief review of the aspects of perforations that seem relevant to Przedborz stamps, i.e. to methods that might have been used in Poland prior to the mid-1920's.1

It is based on the following sources, listed in no particular order:

Too late to be included in the initial writing of this section, I found some interesting websites:
The Austrian Philatelic Society of Great Britain has an interesting summary of perforation issues relevant to them, and interesting to us because Przedbórz was occupied by Austria-Hungary starting in about February 1915.

A (Partial) Taxonomy of Perforations.
  1. Method of Perforating, or type of machine used.
    Note: At this time, I have no idea what types of perforators might have been available to Panski, who printed the genuine stamps, but Williams [1990] seems to suggest that at least some of the forgeries were single-line-perforated.
  2. Pattern of Hole Production.
    There are several types and subtypes of the pattern of punching the holes. (This wording is awkward, but may make sense if you keep reading.)
  3. Depth of the Stack.
    It was common to perforate several sheets at a time. Williams [1990] illustrates (pg. 712) a Grover perforator punching seven sheets at a time, but this was after World War II. I imagine that earlier, 3-4 sheets was the norm.
    Herb Volin has suggested that the variation in Przedbórz perforation quality is due to trying to punch too many sheets at one time; this must have been especially common when punching the forgeries.

    Tim Burgess points out that in the major developed countries, such as the U.S., Great Britain and France, printers (of genuine stamps) were better trained and supervised. In such cases, rough perfs were more likely to arise from poor maintenance of the perforation machines. Examples might be bent or broken pins, chad not removed, etc. 2
  4. Shape of the holes
    Most perfs have round holes, but some perforators punch holes that are oblong, oval or elliptical (e.g., Great Britain in the 1990's), square, rectangular (e.g. Schermack) or slotted.
  5. Hole Quality
    Usually perforation holes are clean-cut, i.e., the paper has been entirely removed from the hole. However, holes can also have
  6. Irregular Lines.
    While genuine stamps may have perforation irregularities, forgery perforations are much more likely to be irregular. Williams [1990] discusses several causes (pp 726-729).
  7. Freak or "wild" perforations include those going at odd angles, as shown in the Przedbórz #18 foldover error. They are discussed, for example, by Williams [1990, pp. 768-769], and by Boyarsky [2010, pg. 1047], who calls them "wild" perforations.


Examples of combs, from Williams [1990]


Single Comb (left): This would perforate (for example) the right side, top and bottom of one column of stamps; when the final side was perforated, the selvage would be perforated as well.
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Triple Comb: (right): This works the same way, but perforates three columns at a time, thus requiring fewer passes through the perforator.













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Five-Comb: (right): This works the same way, but perforates five columns at a time, requiring even fewer passes.

A Harrow is a comb with enough columns to perforate an entire sheet in one pass.

Look at Przedbórz perforation samples, or go back to varieties

Footnotes:
1. The untested assumption is that most forgeries were printed in Poland no later than the mid- to late-1920's.

2. Ray Simpson points out that the perforating pins could become worn. After all, paper is a very abrasive material, although many people don't realize it.

Also note that perforating happens after the gum is applied; otherwise stamps would stick together when you tried to separate them. So it's easy to imagine the perforating machine getting sticky, dirty, and generally clogged up, unless it was cleaned very frequently.


Last modified 30 Nov. 2014