Perforations—or lack thereof—offer collectors one of the most significant means of identifying and categorizing stamps. All stamps issued before 1854 lacked perforations, so clerks and patrons used scissors to separate a stamp from the others printed on the same sheet. This was inconvenient and especially time consuming. Then in January 1854 Great Britain issued its Penny Red with perforations, a move welcomed by patrons. Three years later the United States issued its first perforated stamp, the 3-cent Washington. For the next hundred and forty years printers produced most stamps with perforations. Those inadvertently issued without perforations are categorized as "errors."
One of very few imperforate examples of the 1934 federal duck stamp known to exist, this vertical strip of three is either a genuine error produced during the perforation process or "printer's waste." If printer's waste, it is not a genuine error since it was actually meant to be discarded, in which case it undoubtedly entered the marketplace illegally, removed from the printing floor by an unscrupulous employee. All known examples lack gum and are supposedly from a pane of twenty-eight.