Banknotes Numismatics

US Paper Money Varieties Guide 2026

How series dates, signatures, seal colors, and printing errors affect banknote value.

PreGradeCards Newsdesk Published Jun 28, 2026 Updated Jun 28, 2026 4 min read
US paper money varieties by series and seal color

The Short Answer

  • Series dates and signature combinations identify the issuing era.
  • Seal colors include red, blue, green, brown, and yellow.
  • Printing errors like ink smears and mismatched serials can be valuable.
  • AI can identify series, signatures, and seal colors from photos.

Series Dates and Signatures

US banknotes display a series date and the signatures of the Treasurer of the United States and the Secretary of the Treasury. Different combinations create collectible varieties.

Seal Colors

US paper money has used several seal colors. Red seals are found on United States Notes, blue seals on Silver Certificates, and green seals on Federal Reserve Notes. Older notes may have brown or yellow seals.

Printing Errors

Banknote printing errors include ink smears, mismatched serial numbers, missing prints, and foldovers. These errors can be valuable if the note is otherwise in good condition.

AI Identification

AI can identify series dates, signatures, seal colors, and serial numbers from banknote photos. This helps collectors quickly catalog and value their notes.

Frequently Asked Questions

What does the series date mean on a banknote?
The series date indicates when the note design was authorized or updated, not necessarily the year the note was printed.
Are red seal notes worth more?
Red seal United States Notes are often collectible, but value depends on the specific series, denomination, and condition.
What are common banknote printing errors?
Common errors include ink smears, mismatched serial numbers, missing prints, and foldovers.
Can AI identify banknote seal colors?
Yes. AI can detect seal colors and read series dates and signatures from banknote images.

Sources & Further Reading

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