Authentication Glossary
The terminology used by forensic analysts and serious collectors to describe signature characteristics and flaws.
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Autopen
A machine used to automatically reproduce a person's signature. Originally designed for politicians, heavily used by astronauts and musicians. Detected by perfectly uniform pressure and microscopic dots at stroke terminals.
Bleeding (Ink)
When ink spreads outward from the original stroke into the fibers of the paper or leather. Often indicates a modern marker used on vintage material, or exposure to high humidity.
Clubhouse Signature (Secretarial)
A signature signed by a bat boy, clubhouse attendant, or secretary on behalf of the athlete. Extremely common on vintage baseball team-signed items. Not authentic to the player.
Exemplar
A verified, undeniably authentic signature used as a baseline for comparison. Strong exemplars come from legal documents (contracts, checks) rather than hurried in-person signatures.
Foxing
Age-related spots and browning on old paper documents, caused by the oxidation of iron, copper, or other impurities in the pulp or rag from which the paper was made. Affects grade but generally not authenticity.
Hesitation Marks
Microscopic pooling of ink indicating the signer paused. A massive red flag for forgery, as authentic signers rarely pause mid-stroke when signing their own name.
Provenance
The documented history of an item's ownership and origin. Strong provenance (e.g., photo of the signing, original receipt from charity auction) supports authentication but does not replace forensic ink analysis.