Artist Trading Cards

I was reading an article in a kids' crafts magazine about Artist Trading Cards. For a recent Art Therapy supervision, I had everyone make a card based on how they were feeling at the time or what was going on at the time with them. I think this could be used as a directive in Art Therapy groups, especially with kids or teens. The two rules for Artist Trading Cards are that they must be 2.5" x 3.5" and they can only be traded, not sold. I made my own blank cards using bristol board. You can buy baseball card sleeves to hold them. Check out the website www.atcsforall.com for more info.