This is a sketch that was created before the original artwork. Initially, the sketched version was intended to be the final artwork. However, after inking the main element, the paper did not respond nicely to the pigment. Despite this, the artist did not want to dispose of it because he was happy with the overall layout. So, he started all over again on a much thicker paper and decided to frame the first attempt.
 
Now, the first version is available for purchase. You can enjoy it as the artist does having it in the gallery.