Artist Trading Cards (ATC's) have to measure 3.5 x 2.5 inches and they have to be traded not sold. Those are the only 2 rules. Apart from that, anything goes!

They can be made using any theme, style or techniques - and it is quite fun trying out new stamps or stash on them.
I am also part of a small international ATC swapping group of around a dozen - so I get the chance to make and receive lots of these little treasures!