Sketch cards are original artwork drawn on 2.5″ x 3.5″ trading card stock. Trading card publishers commission artists to produce one-of-a-kind sketch cards for insertion into sets, usually one per box.
These galleries feature sketch cards from DC Comics trading card series. Hundreds of cards are commissioned for each set and the complete number of sketches is unknown. There are likely many more Supergirl sketch cards from the more recent sets still to be discovered.
DC Comics: Superman: The Legend (Cryptozoic, 2013)