OK, I've washed and dried my test pieces of fabric. I only tested the Sharpie and the Bic permanent marker since that's what I had at the time. I ironed them before washing them and line dried them. They all came out just fine, but I think the Bic was a bit sharper (no pun intended). It was a decidedly unscientific test though...
I have to dig around for the Crayola markers that I know I had at one time.