1/1 (one of one)
A card with a print run of one. Topps calls the 1/1 the rarest type of trading card.
Where this definition comes from
A 1/1 card is the rarest type of trading card, making it especially appealing to collectors.
Topps Ripped glossary: One of one, read
Definition written from the quotes above, last checked . RookieDesk is not affiliated with the companies quoted.