For those who is still wondering what is ATC, here is the definition I found from Wikipedia.
Artist Trading Cards (or ATCs) are miniature works of art about the same size as modern baseball cards, or 2 ½ X 3 ½ inches (6cm X 9cm), small enough to fit inside standard card-collector pockets, sleeves or sheets. The ATC movement developed out of the mail art movement and has its origins in Switzerland. Cards are produced in various media, including dry media (pencils, pens, markers, etc), wet media (watercolor, acrylic paints, etc), paper media (in the form of collage, papercuts, found objects, etc). The cards are usually traded or exchanged rather than sold.
Recently my art nerves suddenly surfaces and I'd been digging back some of my ATCs. Most of them are dated in 2005. wow....5 years ago. Wow...I can't believe it! 5 years. and I'd not been creating anything (except the two bird illustrations and mixed media). Shame on me :( I'd been riding on the craft horses and forgotten about the smell of acrylic paints, sticky fingers with glues, messy table full with papers and ephemeras.
This year my one and only resolution is create more art.