A very interesting Penny Red stamp shown on the image above illustrates the two important issues in philately to which a special attention should be paid to. Perforation misplacement i.e. perforation shift to the left side with perforations distinctly cut into design of the opposite stamp and even more importantly omitted letter at the lower right corner of the stamp.

Perforation misplacement occurs due to misalignment of stamp sheet when placed in perforating machine. Although there are no precisely defined conditions for which a stamp is determined as an error stamp with regards to perforation misplacement, depending on the extent of perforation shift or irregularity it is decided whether a stamp qualifies or not as an error stamp.

Penny Red stamp shown on the image above can serve as an example of a stamp with perforation shift sufficient enough for it to be taken in consideration as an error due to perforations been cut noticeably into design of the opposite stamp. Otherwise, if perforations hadn’t cut so distinctively into the stamp design, it would have been considered just as a stamp with bad centering. It outlines an issue open for debate as there are certainly different views on the subject matter from philatelists. Let us keep in mind that the intention of presenting this particular Penny Red stamp was with the aim of getting a better understanding of what to pay attention to in regards to perforation misplacement. It can be safe to say that stamps with such distinctive appearance of perforation shift are at least considered as uncommon.

A possibility of it being a certain perforation trial is quite viable hypothesis considering the stamp’s specifics and time frame of the presumed trial conducted.

If it should be the case, from the aspect of rareness (Penny Red stamps are the first perforated stamps in the world) and consequently the value of this particular Penny Red stamp would be immense.

Even more importantly, presumed omission error in the lower right corner of the Penny Red stamp would make it a rarity of first order by all accounts if proven genuine by expertizing committee.

By presumed, we have to take in consideration possibility of printed letter I consequently cut out by misplaced perforations (only in the case of P-I corner letters of Penny Red stamp). However, since there is no sign of letter parts i.e. leftover print around perforations in the lower right corner of the stamp as well as perforations going through the “remaining part of square area intended for the letter” of the partially visible opposite stamp to the left, that is highly improbable. Presuming its genuineness, one of the more plausible explanations is that the stamp is a perforation trial, considering all the irregularities (bluish looking paper etc.) found on it.  

Both types of error generally occur very rarely due to quality control during the production as well as inspection and final approval by postal administration prior to stamps release to the public. In the case of the oversight by personnel or due to any other reason and stamps with errors do reach open market they are highly sought after by collectors and usually command high prices.

Stanley Gibbons Great Britain specialized Queen Victoria stamp catalogue Volume I Part I covers extensively early period of British philately with in depth coverage of essays, proofs, trials (both color and perforation trials), plate varieties, watermark varieties etc. In regard to previous “analysis“ of the Penny Red stamp shown on the photo above, of special interest to us would be perforation trials conducted by Henry Archer that are comprehensively described in the catalogue. On this particular example we can see the importance of having appropriate reference literature for correct identification of stamps.