US Major Errors, Freaks and Oddities (EFOs) on Stamps

How Errors Are Made

Philately, according to Websters dictionary: "the collection and study of postage and revenue stamps and other material relating to to postal or fiscal history". More importantly, one becomes a philatelist, or a collector or a dealer because of the love for the stamp.

Major Stamp Error

In the beginning, there was cellulose fibers in suspension in water. Through process of draining the water and separation of fibers into sheets, pressing and drying, the first component of the stamp is born: the paper.

Stamp Making Process - Foourdrinier Machine

If during any of the paper making process the sheet was creased, the sub-sequential process of printing will deliver a stamp with a paper crease error. And here we start the journey of following errors caused by unintentional occurrences during the production of a stamp. These errors can be classified as Major Errors, Freaks and Oddities, also known as EFOs.

Error Created During the Watermarking Process

After the paper making process is completed, the next step in stamp production is the application of a watermark. Watermarks were added to the stamp production process to prevent counterfeits and forgery. The well known example of US watermark error exists on United States 1938-43 Presidential Series $1. Normally, this stamp was printed on un-watermarked paper, but by mistake it was issued on paper intended for revenue stamps with the watermark "U S I R". This unintentional error is qualified by Stephen R. Datz in his "Stamp Collector's Bible" as very valuable and rare error.

Watermark on Stamp

Errors Created During the Printing Process

Once the paper and the watermarks are in place, the next step in stamp production is the printing of the image on the paper. The process between the selection of details to be incorporated in the design to the final transference of the design on the die then to the paper, although fascinating, is not in the scope of this article.

Once the printing starts, so do the majority of errors found in stamps. These errors are result from unintentional occurrences and are classified as Major Errors during the printing process:

  • color-omitted errors (one or more colors missing)
  • inverts (image or frame is inverted relative to the rest of the stamp)
  • color errors (one or more wrong colors applied to the design)
  • double or multiple impressions (sheet run through the printer one or more times)
  • tagging omitted
  • printed on both sides
  • stamp crease (paper crease that happened during the printing)

Color Omitted Stamp Error

Errors that happen during the printing process are considered Freaks or Oddities:

  • albinos (complete absence of one or more colors)
  • color shifts (sheet misaligned with the color application)
  • underinked or overinked (too little or too much ink)
  • offsets (ink intended to one sheet is deposited on another)
  • foldovers (a corner of the sheet gets folded over or under)
  • unprinted areas (caused by foreign material deposited on sheet to be printed)

Fold-over stamp error

Errors Created During the Gumming and Separation Processes

Next step in the process of making a stamp is the gumming (sometimes this step comes before the printing) and separation.

These are errors that can occur as a result of an unintentional mistake during these last phases.

Major Errors:

  • imperforate (stamps should be separated but weren't)
  • gutter (lack of separation of press sheets from panes)
  • perforations other than normal gauge (too big or too small)
  • gum error (gummed when not supposed to and vice-versa)
  • gummed on both sides

Imperforated Error Coil

Freaks and Oddities:

  • misperforated (perforations shifted from normal position)
  • miscut (misaligned sheets going through cutting equipment)
  • blind perforations (perforations that do not completely go through the paper)
  • imperforate margins (omitted perforation between the stamp and sevage)
  • multiple perforations (combination of one or more things going wrong during the perforation)
  • partially imperforate (some perforations missing or incomplete)

Miscut Stamp Error

The production process of a stamp is completed at this point. Please refer to additional articles on this site for more exciting information about stamps with mistakes.

This website is dedicated to the philatelists and collectors that are interested in the fascinating field of US Errors in Stamps.