ATC stands for "Art Trading Card". The only rules for these are that they must be of the dimensions I described above and they cannot be sold for money. ATCs can only be given away or traded for someone else's card. There are many trading groups in Yahoo and elsewhere on the internet (a search can easily be done for them) dedicated to the trading of these cards.
ACEO stands for "Art Card Editions and Originals". The only rule for these is that they must be of the dimensions I described above. They can be original works or copies of an original work and are sold to other artists and collectors of them. Ebay has an enormous section on it's website devoted to this as do other websites. They can be found with any search engine. ACEOs can be sold for anywhere from $.01 to $300 and up.
They can be created horizontally or vertically as long as they meet the dimension rule. Although the majority of the cards are done on paper with the average artist materials ATCs or ACEOs can be created in any art form imaginable: painting, collage, stamping, photography, 3-D, clay, sewing, leather, metal, plastic, cloth, and on and on. Any materials can be used, paint, pencil, pen, glue, glitter, buttons, sand, beads, pieces of jewelry, just anything your imagination can dream up. Again, the only rule is that they must measure 2.5" X 3.5" vertically or horizontally. Collectors of them keep their collections in baseball trading card-like binders, boxes, books, and all sorts of creative places.
I'm going to post a few here that I did in watercolor on Arches 140lb cold press paper a year or so ago, and in the event someone looking here would like to know more about ATC/ACEO's I'll list a few website links that you can connect to from this blog to learn more about them, purchase supplies to make them with or collect them in. You'll also see other examples of them on these links. Enjoy!
"Petunia Blossom" 2.3" X 3.5" Watercolor
"Two Beauties" 2.5" X 3.5" Watercolor
"My Kind of Gang" 2.5 X "3.5" Watercolor
"Long Island Sound" 2.5" X 3.5" Watercolor
"Magnolia Blossom" 2.5" X 3.5" Watercolor
"Buddies" 3.5" X 2.5" Watercolor
"Close Up" 3.5" X 2.5" Watercolor
I hope you enjoyed today's post and here are those links to websites that will further explain these fun little gems for you. Some of the sites will have other links listed that you can connect to to learn even more about them, particularly the last link I've given you: