What an Autopen is and How to Detect it March 02 2026

An autopen is a machine that uses a real pen to mechanically reproduce a person's signature. The device relies on a custom-made plastic disc or matrix—created from an original handwriting sample—which guides a mechanical arm holding the pen.

First gaining prominence in the mid-twentieth century, autopens are heavily utilized by U.S. presidents, politicians, astronauts, corporate executives, and celebrities who receive too much mail to sign personally. In addition to signatures, the machine can be programmed to write short inscriptions like "Best Wishes" or draw small symbols like a heart or a smiley face.

[An example of an autopen signature of the famous actor Clark Gable (1901-1960)]

Because the autopen uses real ink and a real pen, the results can easily fool an untrained eye. However, experts use several key characteristics to detect them:

Exact Matching (Superimposition): The most certain way to detect an autopen is by superimposing the questioned signature over a known autopen example using a light table, window, or clear acetate overlays. Because no human signs exactly the same way twice, if two signatures match perfectly in their proportions and letter formations, they were created by a machine. Collectors must be thorough, however, because celebrities often own multiple different matrices.

Uniform Pen Pressure: Natural human handwriting features variations in speed and pressure, resulting in light upstrokes and heavier downstrokes. In contrast, an autopen applies a constant, monotonous pressure throughout the entire signature. This gives the writing a "flat" appearance, and because the machine writes slower than a human, the ink may soak into the paper more heavily.
Machine Tremor: The mechanical nature of the autopen often causes telltale shakiness, jagged areas, or wavering in the strokes due to machine vibration. Sometimes, if the pen is adjusted too heavily, the drag creates vibrations so severe that the signature looks like it was written by someone suffering from a medical tremor.

[Another example of an autopen signature of the actor and screenwriter John Gilbert (1897-1936)]

Ink Dots and Blunt Endings: When the machine drops the pen to begin writing or lifts it at the end, it often leaves a sequence of overlapping dots or small pools of ink. Additionally, the ends of the strokes will frequently appear blunt and abrupt, lacking the natural tapering or "flying" stops and starts produced by a swift human hand.

When comparing a suspect signature to a known autopen template, you should also note that slight variations can sometimes occur if the paper shifts during signing or if different thicknesses of pens are used. In those cases, focusing on the exact form and spacing of the letters, rather than their precise position, will reveal the machine's underlying pattern.

[Leopold Stokowski (1882-1977) - A beautiful photograph with an autopen signature of the famous British conductor best known for his long association with the Philadelphia Orchestra during a rehearsal in his elder years]

OTHER RELATED BLOG ARTICLES:

- Damaged Photos: Guidelines to Types of Damage

- Glossary of Autograph Terms

- How to Protect your Autographs from Fading

- Archival Framing: 10 Best Recommendations to Protect your Autographs

- Autograph Dealers Fake vs Real - 12 Things to Consider

- Autograph Value: How to Find It and Other Autograph Worth Questions

- Autograph Collecting 101: A Beginner’s Guide

- Facsimile Autograph: How to Detect Printed Signatures

- How to Know When an Autograph is Authentic

- How to Avoid Buying from Fake Sites

- Autograph Authenticity: Is Authentic, Enough?