Artist Trading Cards are 2.5X3.5" inch miniature works of art. They can be made from almost any medium and are only limited by your imagination. There are groups around the country where they hold "sessions". At the sessions you can view, meet other ATC artists and of course, trade! ATCs are never sold, they are only traded. Besides being so darn cute, I love them because you can actually finish a project in one sitting, which is so great for busy moms who would still like the therapy of crafting, but don't have a lot of time to do it. Budget wise, it has to be one of the cheapest forms of creativity!!! Anything from stamps off the mail to scraps of paper from your last crop can be used. Cut up magazines or get out your watercolors; it doesn't matter, just whatever inspires you! The company 7 Gypsies makes wonderful ATC products from a spinning carousel for displaying your cards to vintage library drawers to keep them in as well and all kinds of products to create your ATC. If you go to Google images and type in "Artist Trading Cards" tons of images of the mini creations will pop up so you can get a better idea of what they're all about. I like mine to send a mini message if I can or rather, a bit of inspiration to add to my work space. You should always sign and date the back of your little works. Here's a link to another wonderful ATC supplier if you'd like to buy the protective clear envelopes to keep them in. http://www.youratcstore.com/ You can leave the corners sharp or round them like I did. Give 'em a try! Even if you never trade them, they're fun to make and a treasure to keep or give to friends.