Update: October 9th 2012
Due the intense demand of incoming art submissions I can no longer keep up with posting personalized reasons for why art was rejected. If your art is rejected here's the top reasons WHY:
#1 - You picked 'Black and White' from the drop down menu.This is by far the most common mistake. When submitting art, always pick the correct folder to submit it to. 'Black and White' must contain NO COLOR. Always check before you hit 'Submit', an extra ten seconds will save you having to resubmit and wait longer for your art to be accepted.
#1.a - Picked a folder that is incorrect in general. Animation? That's for art that is animated, gifs, pngs, actual animations posted as well. What doesn't belong there? Skull fanart from a movie. I get a few images submitted here and there that are in the wrong folder, drawings sent to sculpture, people still trying to use the Halloween contest folder, and so on.
#2 - Your art is not clear/clean/or well photographed.While we have no skill level requirement we do want your art to well presented. When taking photos of traditional art, crop out any of the background, and make sure it's well lit. Grainy/blurry/or overly light drawings risk being rejected. Digital art too should be clean and clear, overly filtered art full of pixels that make it hard to tell what the heck it's actually a picture of will likely be rejected.
If you can see your bedroom in the background, it's not well cropped. If I can see the whole of the spiral bound notebook you drew it, it's not well cropped.
#3 - Not listing stock photo sources.This one is becoming more common. Even if it's YOUR photos you used, just make a note in the comments. Respect the original creators of stock images. Yes I do check each and ever manipulation submission for credits.
#4 - There's no skulls!You'd be surprised but yes, I have rejected art here that contained no skulls. We're pretty loose in what's a 'skull', as skull like markings, or boned platted alien creatures are all welcome, but photos of your sister, not so much.
#5 - I've checked my art and I don't think any these apply to me..and I was rejected?We're all human, it might have been an honest mistake (Fingers slip! And those accept/reject buttons are kind of close..). If you're sure you submitted your well cropped photo of a deer skull painting to the Traditional art folder, you can send us a note, or leave a comment on the submission rejection itself and ask why.
And remember, you can ALWAYS resubmit should you find your art rejected.