Miniature fountain pens seem to have made their appearance in the wake of those novelties at the other end of the spectrum, the giants (see above). The earliest miniatures (and the most common) appear to have been the Peter Pan pens, sold by Salz Brothers of New York City. These were hard rubber ringtop eyedroppers with gold nibs, often with colored casein cap tops. Aikin Lambert offered the same pens under their imprint, labelled "The Pet", but it is unclear who was the actual manufacturer. Colorful celluloid models followed: first eyedroppers, then lever-fillers, including models with applied floral decoration.
Waterman made the smallest and most highly prized miniatures, known variously as the "Doll's Pen" or "The World's Smallest". These were minuscule black hard rubber slip-cap eyedroppers, although a few are known in red hard rubber, and safety versions were also made.