Wondering whose sketchcard you pulled from Unbound? (Probably not, but more on that in a sec...) Some artists are easy to tell, other artists' scribbles are not so obvious. Some have an artistic flourish of sorts on the front. When found, those are below as well. A couple of brief notes:
Unbound was a weekly ePack-only set. One character card was released each Monday at noon EST. There was a base card and a signed parallel, so it was a pretty straightforward set. All artwork was completed by fred.ian.
The first year there were a small number of sketches, but only as achievements.