An autopen (or signing machine) is a device used for the automatic signing of a signature. Prominent individuals may be asked to provide their signatures many times a day, such as celebrities receiving requests for autographs, or politicians signing documents and correspondence in their official capacities. Consequently, many public figures employ autopens to allow their signature to be printed on demand and without their direct involvement. Though manual precursors of the modern autopen have existed since at least 1803, 21st-century autopens are machines that are programmed with a signature, which is then reproduced by a motorized, mechanical arm holding a pen. Given the exact verisimilitude to the real hand signature, the use of the autopen allows for a small degree of wishful thinking and plausible deniability as to whether a famous autograph is real or reproduced, thus increasing the perception of the personal value of the signature by the lay recipient. However, known or suspected autopen signatures are also vastly less valuable as philographic collectibles; legitimate hand-signed documents from individuals known to also use an autopen usually require verification and provenance to be considered valid. Early autopens used a plastic matrix of the original signature which is a channel cut into an engraved plate in the shape of a wheel. A stylus driven by an electric motor followed the x- and y-axis of a profile or shape engraved in the plate (which is why it is called a matrix). The stylus is mechanically connected to an arm which can hold almost any common writing instrument, so the favourite pen and ink can be used to suggest authenticity. The autopen signature is made with even pressure (and indentation in the paper), which is how these machines are distinguishable from original handwriting where the pressure varies. History The first signature duplicating machines were developed by Englishman John Isaac Hawkins. Hawkins received a United States patent for his device in 1803, called a polygraph (an abstracted version of the pantograph), in which the user may write with one pen and have their writing simultaneously reproduced by an attached second pen. Thomas Jefferson used the device extensively during his presidency. This device bears little resemblance to today's autopens in design or operation. The autopen called the Robot Pen was developed in the 1930s, and became commercially available in 1937 (used as a storage unit device, similar in principle to how vinyl records store information)