Ink Timeline Reference
A critical step in authentication is ensuring the ink existed when the subject was alive.
Major Ink Introduction Dates
- Iron Gall Ink: Standard from Middle Ages to mid-20th Century. Highly acidic, often burns through paper over time.
- Fountain Pen Dyes (Aniline): 1860s onward. Water-soluble, prone to fading.
- Ballpoint Pen (Biro): Commercially viable in 1945. Any "ballpoint" signature dated before 1945 is highly suspect.
- Felt Tip (Magic Marker): 1952.
- Sharpie Fine Point: Introduced in 1964. The most common modern autograph medium.
- Paint Pen (Posca): Early 1980s.