These are kind of fun. They are the same size as baseball cards or other such collectible cards (2 1/2″ x 3 1/2″), but they are little treasures of handmade art you trade with your friends. I have some people I trade with regularly, but I also make extras and send them with little packages and things. The small format is perfect for little compositions that can be very quick, or can become very detailed and involved, depending on the time you have. I like them because they are a great way to work out small ideas that might be translated into larger ideas later. Sometimes, I use them as a little warm-up exercise before I sit down to do more involved projects. The sky is the limit on media. I’ve lately been doing them with hand-carved stamps, but anything will work, alone and in combination. Try paint, pencils, crayons, embossing, or collage. I’ve even seen some embroidered ones. Lately, I’ve been trying to “get off the card.” I’ve been trying pop-ups, fold-outs, and other moving elements. This one is a stamp I made of a character from the movie, The Nightmare Before Christmas, by Tim Burton. There are two different faces, stamped separately on a little strip. When you pull the strip from the side, the face changes. Give it a try. They are really fun.