These are miniature trading card sized original paintings. ACEO stands for Art Cards Editions and Collectibles. They fit beautifully in trading card books and frames designed for baseball cards. The current price rule I follow my ACEOs is a base price of $10 plus extra for paintings that are more detailed, type of paper used, and time it took to paint. Sometimes my detailed ACEOs can take almost as long as a much larger size painting to produce. I hope you enjoy these one of a kind collectibles as much as I enjoyed painting them!