Perforations: the Hole in the Corner

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Original written by Martin Brumby

As Packet Secretary, one task I have to carry out is to check through every book of stamps before it goes on circuit and again on its return. I check that everything is ‘as described’. Most sellers are pretty reliable but the one area where errors frequently creep in, is the identification of perforation varieties. Even some respected and advanced philatelists seem to have some problems here. So perhaps it may be worth doing a little ‘revision’.

The most comprehensive work on Austrian perforations is that by Dr. Helmut Pfalz and Mag. pharm. Helmut Richter: "Österreiche Spezialkatalog – Amtliche Zähnungen 1867–1906 (Published by the authors. APS Library No. 36). They point out, right at the outset, that the key for successfully collecting the different perforation varieties is an appreciation of the three basic perforation types (sheet or harrow perforation, row or comb perforation, line perforation) "and only secondarily an acquaintance with the perforation gauge". They go on to describe the different types as follows:

Perf. 10 harrow

Perf. 13 x 12½comb

Perf. 11½ line

Features of sheet perforation (harrow perforation)

"With sheet perforation, the perforation pins in the perforation machine are arranged in little rectangles or boxes (hence the German name Kastenzähnung) the size of the individual stamps. There are as many of these boxes as the number of stamps in the printed sheet. Accordingly, with the downward stroke of the perforation apparatus, all the perforation holes in the underlying sheet of stamps are punched in a single process. From this mode of operation of the perforation machine it follows that the corners of the individual stamps are all the same and of regular appearance and the individual stamps are all of an equal size." (my emphasis).

Features of comb perforation (row perforation)

"Comb perforation is today the most common kind of perforation. The pins are here arranged in the form of a comb. The perforation process is automatic. The perforation mechanism with the pins ordered in a comb shape rises after perforating the first row of stamps (thus perforating three sides of the top row of the sheet of stamps). The sheet of stamps is now advanced to the position of the next row of stamps, this is then perforated and so on to the last row of the sheet. With flawless operation the automatic perforation machine naturally also produces stamps of equal size and each stamp, horizontally and vertically always exhibits the same number of teeth. The corners of the stamp, as with sheet perforation, are all equal and regular. Irregularities in the operation of the perforator lead occasionally to shortened stamps or to stamps with broadened corners, which does not, however, thereby change the basic characteristics of the perforation."

It should be added that any really noticeable irregularity along these lines would be quite collectable in its own right.

Features of line perforation

"With line perforation the perforation device consists only of a single row of teeth, where the perforation pins stand out in a straight line. The upper edge is first of all punched with this row of pins, then the sheet of stamps moves forward the height of a row of stamps, the machine then punches the next row of stamps at the upper edge and so on, until the lower sheet margin is reached. Thus the sheet of stamps is perforated horizontally. Now the sheet of stamps is turned through 90 degrees and in the same way the vertical perforations carried out. Accordingly for a sheet of stamps of 10 x 10 stamps, 22 different processes are necessary. In this way, all the classic Austrian stamp issues with line perforation had to have each individual perforating operation carried out, mostly by hand.

It is thus understandable, particularly through inaccurate work, that the distances between the individual rows of holes slightly differ and therefore the individual stamps within the each sheet of stamps may be of different sizes. (So-called long or wide formats, often abused to produce dangerous fake perforations.) It is furthermore clear, that with such a mode of operation the perforation rows cross each other irregularly, the number of the teeth of individual stamps therefore varied according to size of the stamps and the various positioning of the perforator. Also the corners of the stamps when compared to each other, present a completely irregular appearance."

Characteristics of the individual perforation types

Pfalz and Richter continue: "The characteristics of the corner perforations tell us whether we are looking at a stamp with harrow or comb perforation, or else one with line perforation. We can and must make this differentiation only by considering the perforations characteristics and without use of perforation gauges. The distinction between harrow perforation and comb perforation is therefore not important, because any confusion between these perforation types (perf. 9½ and 10 harrow or 13x12½ and 13x13½ comb) is anyhow impossible. To again explain the differences between harrow or comb perforation on one hand and line perforation on the other hand as clearly as possible, refer to the illustration above (regular corners with harrow or comb perforation, irregular with line perforation)."

It should be added that a stamp with irregular corners CANNOT be harrow perforated. Whilst, by a fluke, the strokes of a line perforator might yield a fairly regular corner to a single stamp (see the lower left corner of the stamp illustrated above), it is almost impossible that any specimen might be found with four regular corners, especially when checked under a magnifying glass.

Our authors continue: - "Frequently these characteristic distinctions are not considered when examining the perforations of the individual stamp. The beginner measures straight away with the perforation gauge - without paying attention to the characteristic corner perforations - and is led astray, when considering an 1867 stamp measuring perf 9 or an 1883 stamp measuring 10½. The beginner then is led from the fact that no harrow perforation 9 or 10½ is recorded, although there are line perforations in these gauges, to firmly resolve that the stamps examined must be line perforation 9 or 10½. The beginner should therefore consider the following:

"Through the long period of use of the harrow perforation machines (particularly the issues of 1867 and 1883) inaccuracies emerged. Perforation pins had become worn or broken and had been renewed inaccurately. The imperfections with the old harrow perforation machines had become so great, in the case of the 1883 issue, that eventually sections of the perforation pins were broken out and replaced with too many or too few new pins, so that the number of perforation pins on corresponding sides of the perforation rectangle were not all equal [**]. It is thus clear, that under these circumstances the perforation fluctuates and the perforation gauge does not help much at all. [++] Thus for the collector of perforation varieties of old Austria, once again the most important basic rule is repeated:

Before using perforation gauges it must first be ascertained whether the stamp is harrow or comb or, alternatively line perforated. If the stamp has the characteristics of harrow or comb perforation then that is what it is. But if it has the line perforation characteristics, then it is line perforated, irrespective of what it measures on a perforation gauge. In this case an 1883 stamp with irregular corners measuring 9½ must be perf. 9 or 9½ line, one measuring 10 must be perf. 10½ line. And conversely, an 1883 stamp with regular corners must be perf. 9½ or 10 harrow."

[** Such a case is described as "irregular sheet perforation". With the ordinary sheet or harrow perforation the number of teeth or perforation holes on each stamp above and below is exactly the same, likewise on the right and on the left. The irregular sheet perforation, which occurs exclusively with the issue of 1883, breaks this rule. See Pfalz & Richter - or Ferchenbauer.]

[++ It is also worth pointing out that the "perf. 10 harrow", more often than not actually measures 10¼!]

Compound Perforations

"Compound perforation is a sub-type of line perforation. This derives from the case where the same sheet of stamps is perforated by two different perforators in different directions. First of all the horizontal perforations are carried out with one perforator across the sheet of stamps, then the same sheet of stamps for the vertical perforation is inserted in another perforation machine. If the two machines use lines of pins set at different intervals, the perforated sheet of stamps shows horizontally one perforation and another vertically. A stamp in normal compound perforation thus shows above and below one gauge and down both sides another.

Sometimes it also happened during normal line perforation that a line of perforations was not properly punched. In consequence stamps remain joined together and are described with the familiar philatelic term Imperforate between. "

The Stamp Issues

Pfalz & Richter go on to discuss the stamp issues between 1867 and 1906 in considerable detail and also give many insights into the period of use and detailed characteristics of the different perforators. This information is an excellent starting point for the advanced collector. It would be an interesting project for a collector to integrate and expand this information to include other stamps produced (and perforated) by the Imperial Printing House including Austrian, Bosnian and some Hungarian both postage and revenue stamps, the telegraph stamps, one issue of Serbia and all issues of Montenegro and so on. Even postal stationery letter cards may well have used the same (line) perforators? As there can’t have been an infinite number of machines available at any one time, it would be interesting to see what parallels and what differences, might be revealed by detailed comparisons of the different issues.

The Time Factor

Amongst much other information, Pfalz & Richter give outline periods of use of the different perforators (on Austrian postage and postage due stamps). These may be worth reproducing here, whilst remembering that later use (within the period of validity) is just possible but significantly earlier use is extremely unlikely. This provides a useful check and safeguard against at least some faked items.

1867 Issue of Stamps

Issued 1 June 1867 (25kr & 50kr on 1 Sept. 1867), valid for use (in Austria) until 31 October 1884. Only "fine" prints were issued line perforated (some coarse prints line perforated are known but are thought to be unissued trials)

Perf. 9½ harrow2, 3, 5, 10, 15, 251867 to 1883
Perf 9 line2, 3, 5 (T.IIa, IIb), 10, 151878 to 1883
Perf 10½ line2, 3, 5 (T.IIa, IIb), 10, 151877 to 1883
Perf 12 line2, 3, 5 (T.IIa), 10, 15, 501877 to 1878
Perf 13 line2, 3, 5 (T.IIa), 10, 151877 to 1878
Comp. perf. 10½:9 line & 9:10½ line2, 3, 5 (T.IIa, IIb), 10, 151877 to 1883
Compound perfs (others)Various 2, 3, 5 (T.IIa), 10:
see Pfalz & Richter for details
1877 to 1878

1883 Issue of Stamps

Issued 15 August 1883, valid for use until 30 June 1891.

Perf. 9½ harrow2, 3, 5, 10, 20, 501883 to 1887
Perf. 10 harrow2, 3, 5, 10, 20, 501887 to 1890
Perf 9 line2, 3, 5, 10, 201883 to 1884
Perf 10½ line2, 3, 5, 10, 201883 to 1884 (sharp perfs)
Perf 10¼ line


1890 (blunt perfs)
Perf. 9¼ line51890
Perf 11½ line51890
Perf 12 line51890
Perf 12½ line2, 3, 5, 101890
Compound perf. 9:10½ line2, 3, 5, 101883 to 1884
Compound perf. 10½:9 line2, 3, 5, 101883 to 1884

1890 - 1896 Issues of Stamps

Specialists recognise (at least) three different types of paper (type I: hard, translucent, until 1896; type II: softer, smoother, from 1894; type III: whiter, softer, smoother, from 1898) used for this issue. For further details see Ferchenbauer etc. This is another factor which will assist in dating individual stamps and helping to verify whether one of the rarer perforations has been faked.

Perf. 10 harrowI, II, IIIAll kreuzer values1890 to 1898
Perf. 9¼ lineI, IIAll 1890 values, 1891 30kr1890 to 1891 (<1895)
Perf. 9¾ lineI, II1890 values 1 kr – 30kr1890 to 1891 (<1895)
Perf 10½ lineI, II, IIIAll values1890 to 1900
Perf. 11 lineI, II1890: 1 kr – 30 kr, 1 fl
1891: 20 kr – 50 kr
1890 to 1896
Perf. 11½ lineI, II, IIIAll values1890 to 1898
Perf. 12I, II1890 values 2kr – 30kr, 1 fl1890 to 1891
1 fl to 1895
Perf. 12½ lineI, II, III1890 values 1 kr–15 kr,
30 kr, 1 fl, 2 fl
1891 all values, 1896 1fl
1890 to 1892,
occasional until 1894,
& 1897 to 1900
Perf. 13 lineI, II1890 values 1kr – 5 kr,
15 kr, 30 kr, 1 fl, 2 fl.
1890 to 1892, 1 fl
& 2 fl to 1895
Perf. 13½ lineII, III1890 values 1kr-15kr,
1891 all values
1894 to 1895,
1898 to 1900
Perf. 13 x 12½ combIII1890 values 1 kr – 15 kr1898 to 1900
Perf. 13 x 13½ combII1890 5 kr1894
III1890 values 1 kr – 15 kr1898 to 1900
Compound perfs See Pfalz & Richter!!1890 to 1892;
1898 to 1900

Note: Pfalz & Richter consider papers and dates in italics as ‘exceptional’.

1894 Issue of Postage Due stamps

Issued 1 February 1894 (2 kr, 6 kr, 7 kr: - April 1895), valid until 30 September 1900. It is perhaps a comment on human nature that collectors who optimistically see ‘line perforations’ everywhere in the 1867, 1883 and 1890 issues, suddenly ‘discover’ the scarce ‘perf. 10 harrow’ when sorting their 1894 postage dues for sale.

Perf. 10 harrow1, 3, 5, 10, 20, 501894 to 1895
Perf. 10½ lineAll values1894 to 1900
Perf. 11 line1, 3, 5, 10, 20, 501894 to 1895
Perf. 11½ lineAll values1894 to 1898
Perf. 12½ line1, 2, 3, 5, 101898 to 1900
Perf. 13½ line1, 51898 to 1900
Compound perfs1, 2, 3, 5, 6?, 10, 20?,50?Needs more work!

Issues 1899 – 1918

Although there are perforation varieties (some very scarce!) in the later issues, misidentifications are less common (with the exception of the 1899 perf. 12½ line and perf. 13 x 12½ comb stamps and the corresponding perf. 12½ x 13 comb dues. With even a modicum of care, these can be readily separated.

It should be noted that all the recess printed (engraved, intaglio) stamps before WWII were perforated by line perforators. Supposedly (and most probably) this was because of the varying paper shrinkage associated with the dampening and drying processes required the additional flexibility given by line perforators. This differential shrinkage, especially where sheets of paper might be fed into the press in two directions, leads to the ‘tall thin’ and ‘short fat’ stamps, especially notable in the 1916 and 1917 high values and in the Nibelungen charity issue. But careful comparison and measurement shows that all recess printed stamps from the State Printing Works before WWII can be found in varying sizes. This certainly wasn’t because lots of different plates were prepared! An excellent example can be found in the beautiful 1906 stamps of Bosnia, where differences of a millimeter or more in the length of the printed impression are easy to find. For this reason I am sceptical, to say the least, about the tabulations of "perf. 12¼ line, perf. 12½ line, perf. 12¾ line and compounds" which have been published!


The issues for use in the Levant are almost ‘Cinderellas’ as far as philatelic (rather than postal history) collecting is concerned. Blithely ignored by Pfalz & Richter, the stamps are of course listed by Ferchenbauer but I suspect that someone could put together an interesting philatelic study of the perforations, papers, printings, ‘varnish bars’ etc. These are obviously similar to the corresponding Austrian issues but there do appear to be some differences as well!


Hopefully the foregoing will guide and assist the inexperienced and remind the ‘experts’! Hopefully I will never again have to add the Packet Secretary’s annotation "comb perf when seen by MB!"

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