These cards were not part of the official sets and lack the official stamp that cards included in the set received. Some of the uncut cards shown below are from the Marvel Silver Age set and some are from the Marvel Creators Collection. From what I've been able to tell they come in a few flavors: oversized art that the artist just had fun doing (before or after the sets were done), commissions that artists took to do on extra blank cards they had when they were done with the set, and cards that they just decided not to include when the sets were assembled. The uncut cards are 5.5 x 4.5". Standard cut cards are 3.5 x 2.5". I've tried to make the thumbnails shown here proportionately bigger than their cut counterparts.

A special thanks to fellow sketchagraph hound Andrew Allen for the Castrillo uncut. Above & beyond the call of duty! If any of you spot some nice Dr. Doom sketchagraphs out there, be sure to let Andrew know.