1c Benjamin Franklin Stamp (1908): How to Identify It

• Basic description: 1-cent Franklin, green, double-line watermark, perforation 12.
• Why so many varieties exist: the series used five different designs, two paper types, three printing methods, at least 14 perforation gauges, several colors, and 20 denominations.
• Total documented varieties: the Washington-Franklin stamps were meant to simplify postage but ended up producing 220 major and 99 minor varieties.

The same design was issued in more than one form. Which one you have changes the catalog listing:

• Double-line watermark vs. single-line watermark vs. unwatermarked: Hold the stamp up to the light (or use watermark fluid) to check for a double-line "USPS" watermark pattern (earliest printings), a single-line watermark (later printings), or no watermark at all (from about 1915 onward, when the Bureau switched to unwatermarked paper).
• Perforation gauge differences (perf 12 vs. perf 10 vs. perf 11, etc.): Use a perforation gauge to count the number of teeth per two centimeters along the stamp's edge; the same 1c Franklin design was reprinted at multiple perforation gauges over its 1908-1922 run.
• Same ink color reused on unrelated denominations: The Post Office Department did not have enough distinct inks, so the same green ink was used for both the 1c and 8c values (and other pairs shared purple or blue), which can make color alone an unreliable way to identify the denomination if the numeral is worn or missing.

The design was reprinted for 14 years (1908-1922) across five sub-designs, two paper types, three printing methods and at least 14 perforation gauges, so surviving examples are extremely common but fall into many different collectible sub-varieties.

• Measure the perforations with a gauge; the same design often exists in two or three gauges, and that is usually what separates the common one from the scarce one.
• Sheet, coil or booklet: coils have two straight edges on opposite sides; booklet panes have one or two straight edges from the pane edge.
• Tagging: hold it under a longwave UV lamp; tagged and untagged printings of the same design are listed separately.
• Condition (centering, gum, cancel) is a separate question from identification.

Lay the stamp flat on a dark background in daylight, fill the frame, and keep the phone parallel so the perforations are not distorted. Photograph the back too if there is a watermark or gum question. The app reads the design and denomination; the perforation and tagging checks above settle which listing it is.