100 BLANK SMOOTH KRAFT ACEO ATC ARTIST TRADING CARDS ~ DRAWING CARDSTOCK 80# SMOOTH Kraft Cardstock. These are a medium weight cardstock like business cards. THESE ARE NOT WATERCOLOR PAPER. If you are planning to use a lot of water, you may want to find watercolor ACEO cards instead. ACEO ATC Artist Trading Cards. 100% Acid Free and 100% Recycled Cardstock Size: 2-1/2"x 3-1/2" Use Horizontal or Vertical