I'm sorry, this one passed me by a bit and now you've only got till the 10th Nov to submit your cover art. Will it be enough? I don't know. If you name is something like Giotto or Leonardo you might be able to do a quick sketch. Anyway, the facts are here:
The winner's artwork will adorn the cover of the Sampler for first half of 2013. Artwork dimensions should be 198 mm x 129 mm (oriented portrait, as opposed to landscape), and in keeping with the Swan River Press aesthetic.