Artist trading cards (ATCs) is a conceptual art project initiated by the Swiss artist M. Vänçi Stirnemann in 1997. He called it a Collaborative Cultural Performance. Artist trading cards are 2.5 by 3.5 inches in size, the same format as modern trading cards or playing cards. They are self-made unique works or small series, signed and dated on the reverse by the artist/producer, exchanged and collected by the people who participate in the collaboration.

A trading card is a small card, usually made out of paperboard or thick paper, which usually contains an image of a certain person, place or thing and a short description of the picture, along with other text. There is a wide variation of different types of cards.