I was contacted a few months back by a design firm specializing in book covers about the use of an old digital painting I’d posted online for a book cover. Since the original wasn’t nearly good enough resolution for print, I worked with the firm and produced a much better quality replica. There were other changes as well, like beams of light filtering into the cave, a bluer hue, and the addition of butterflies, who are characters in the book.
And for comparison, here’s the original painting, which I made in August of 2009, shortly after I got my tablet. I think it’s one of the first complete digital paintings I did. Having a couple extra years of practice definitely helped. Other helpful factors were a better set of digital brushes and a newer version of Photoshop with improved workflow for digital painting.