Most of my stuff is done primarily with markers. I recently bought a new set of Prismacolor markers with these neat " brush " tips so I broke them in for this. This has colored pencils & some acrylic paint too. Oh, I dunno for sure if it helped but I actually used marker paper instead of just whatever I had laying around as well.I also have a set of Prismacolor pens too. For the outlines, I used umm... some sort of dark umber pen. I have a .005 width and a .05. I dunno if I use markers in the " professional " manner. I kind of use them like I'm painting and there's a lot of saturation.... I don't have much trouble with bleeding though.
I'm sure there are other entries but I haven't thought to look yet.
It was too easy to submit a JPEG actually. Just as long as it's less that 6 MB. I think mine was like 2 MB. But it's one of those deals where it just links you to your own files... like the way it does when you submit something to Deviant Art or... anywhere actually. From what I understand, the winning entries will have to send PSD or TIFF versions, but the key word there is " winning ", so, we don't have to concern ourselves with that yet. Plus, I'm sure they'll be able to help the winners out when the time comes.
Hope that helps.