Paper Money Errors: The Offset Printing
By Benjamin C. Simpson, YN

Few paper money mistakes are more captivating than the offset. It is easy to understand why thiserror type is so popular; their impressive appearance and affordability make them a perfect entrypoint for currency collectors.

Offset printings are roughly analogous to clashed dies for coins. When the impressioncylinder is mistakenly rolled over a wet printing plate without a sheet of notes intervening, the inkdesign on the plate is transferred to the impression cylinder itself. This blunder causes thesubsequent sheets of notes to be printed with its usual design on one face (transferred from theplate) and a mirror image of that design on the other face (erroneously transferred from theimpression cylinder). A reflection has been produced on the opposite side of the note. On allsmall-size U.S. currency, there are multiple printing stages. Offset errors most commonly occur inthe first printing, when most major design elements are produced.

Each time the impression cylinder encounters a wet printing plate, 10-12 error sheets arecreated. Offsets will rapidly decrease in boldness after the first sheet is printed. Collectors payheavy premiums for offsets from the first or second sheets, due to their clarity and eye-appeal.Here is an exceptionally vivid face-to-back 1935E $1 silver certificate, whose offset printing is asbold as the face printing. Offset errors on U.S. Silver Certificate notes are rare.

For more information about the Combined Organizations of Numismatic Error Collectors of America, see:
https://conecaonline.org/