In the “old days” of typewriters, forensic scientists could match a ransom note to the typewriter that produced it to apprehend the kidnappers. This was possible because microscopic differences in the metal letters produced a “typographical fingerprint” that could be identified from any page printed on that typewriter.
As a result, it became fashionable to produce ransom notes with disparate letters cut from a magazine, such as:
Today, computer printers are highly precise instruments that make it nearly impossible to distinguish between pages printed on the same brand printer. However, an article in USA Today describes how many color laser printers leave microscopic yellow dots on each printed page to identify the printer’s serial number and ultimately, you.
Tags: Color Laser Printers, Yellow Dots