US Definitive Series
Also called regular issues.
Period: 1847 onward
The bulk of American philately, and the area where perforation, watermark and printing variety do almost all the work. The same portrait can appear across dozens of catalogue numbers.
What you are looking at
Small-format stamps in long-running series — presidents, Americana, flags, and modern definitives — issued over decades in many varieties.
What to check
- Perforation gauge first — US issues from the same design exist perf 10, 11, 12 and compound, and the differences are substantial in value.
- Watermark: US stamps of 1895 to 1916 carry USPS watermarks, single or double line, and this separates otherwise identical stamps.
- Coil stamps have straight edges on two opposite sides and are separate catalogue entries from sheet stamps.
- Booklet panes have one or more straight edges and specific configurations.
- Precancels — a printed cancel applied before sale — are a large collecting area of their own.
What it is worth
Most common US definitives are worth cents. Value concentrates in early issues, specific perforation and watermark varieties, coils, and errors — and condition, particularly centring, matters enormously.
Confused with
Later official printings of earlier designs, distinguished by paper, gum and perforation.
Questions about this
How do you identify us definitive series?
Perforation gauge first — US issues from the same design exist perf 10, 11, 12 and compound, and the differences are substantial in value. Watermark: US stamps of 1895 to 1916 carry USPS watermarks, single or double line, and this separates otherwise identical stamps.
Are us definitive series valuable?
Most common US definitives are worth cents. Value concentrates in early issues, specific perforation and watermark varieties, coils, and errors — and condition, particularly centring, matters enormously.