I've found that hitting my black sharpie with a hair dryer helps it to not run.
With red and chartreuse sharpies, they will still run, unless I shoot a coat of Createx gloss clear over them.
When I dip and hang a bait by the nose with red sharpie gills without the gloss, the red bleeds down a little, and makes a neat bleeding bait effect.
This old photo shows some bleeding on the right hand bait. At the time I was using AC1315 concrete sealer, and evidently didn't heat set the red well enough, because it bled a little. I did other baits at that time with more pronounced bleeding, but I evidently didn't take any pics.
http://www.tackleunderground.com/community/gallery/image/5484-5-inch-gliderwalkers/