Ordinarily, Fes, you'd be correct, particularly if the cards being made were meant for serious use. Artistic decks, however, get to bend the rules a bit. They're not meant for serious card play so much as for their beauty, and as a collectible, it's also less likely a magician will use them in performance when you factor in what single-print-run custom decks cost and how difficult they can be to find once they're sold out.
My one caution regarding this design is that you might want to lighten up the art just a little, particularly the areas where there's a lot of detail. USPC has been a little ham-handed in the past in regards to contrast, so in a deck's art with a narrow and dark contrast range, many of the details can be lost. They're particularly problematic with black and gray - who remembers Bicycle Venom and Venom Strike? Or even some of the older print runs of Arcane from Ellusionist? They had a LOT of lost details, rendering them a lot less attractive than they should have been. Increasing the contrast range just a bit more at the light end than what you have at present should keep the design from looking like so much mud when it's finally made. As much as we'd like to think that "what you see is what you get," taking an image from your computer screen and printing it on an offset press can occasionally yield rather different results, often not for the better.
