Last month on our forums we had a swap of ATC's . Fun and easy creations showcasing your style of art. Artist trading cards (or ATCs) are miniature works of art 2 ½ X 3 ½ inches . The ATC movement developed out of the mail art movement and has its origins in Switzerland Cards are produced in various media, including dry media (pencils, pens, markers, etc.), wet media (watercolor, acrylic paints, etc.), paper media (in the form of collage, papercuts, found objects, etc.) or even metals or cloth. The cards are usually traded or exchanged. When sold, they are usually referred to as art card editions and originals (ACEOs).