Errors, freaks and oddities on canadian stamps
Errors, freaks, and oddities (EFO) refers to all the kinds of things that can go wrong when producing postage stamps. It encompasses everything from major design errors to stamps that are just poorly printed, and includes both some of the most sought-after and expensive of all stamps, and others that attract the attention of only a few specialists. Canada Post generally take some care to ensure that mistakes do not get out, but some of these mistakes were still sold to the public.
The tagging process is done by overprinting a phosphorescent or fluorescent materiel.
Additional Tagging errors
- Tag smear
This type of error is any of several types of failure in the stamp printing process that results in stamps not having the intended appearance.
Additional Printing errors
- Double overprint
- Missing overprint
- Printed on gum side
This kind of error happens during the perforation process.
Additional Perforation errors
- Partial perforation
Additional Paper errors
- Inverted watermark
- Missing watermark
In the early years of stamp production, gum was manually applied between the printing and perforating process. Nowadays the application of gum is fully automated, with pregummed paper used for the majority of stamps.
Additional Gum errors
- Gummed on both sides
- Missing gum
This type of error is a mistake made during the design phase of postage stamp production process.