First-Issue Fractional Currency
When perusing first-issue fractional currency notes, pay close attention to the width of the paper. Counterfeit notes of this issue usually are thinner than authentic notes of the same denomination. Scrutinize the borders around the inscriptions. The borders should be oval-shaped, and there should be easily decipherable white dots within the band which constitutes the border. Be especially vigilant when reviewing 50-cent notes, as these were the most commonly counterfeited.
Second-Issue Fractional Currency
Authentic second-issue fractional currency notes should have a distinct bronze oval around the portrait of George Washington. The portrait itself also provides for an effective way to detect fakes. Counterfeit second-issue notes have very poor reproductions of George Washington's face. Close comparison of this portrait to an authenticated real note is the quickest way to ascertain whether the note is real or fake.
Later Issues of Fractional Currency
The U.S. Treasury took steps after the first two issues of fractional currency to make them more difficult to counterfeit. Fake notes within the third, fourth and fifth issues are far rarer than in the first and second issues. All counterfeits after the second issue have been found either in the 25- or 50-cent denominations. When reviewing these two denominations, compare the width and the consistency of the paper with a real note. Counterfeiting was especially prevalent within the Stanton series. Pay special attention to Stanton notes, ensuring that each has a red seal. Close scrutiny of the portrait and bands also proves to be a reliable defense against fakes in these later series of fractional currency. According to the National Academy of Science, the government attempted to make later-issue fractional currency waterproof. However, collectors are strongly advised against subjecting notes to water as a check against fakes.