I have used Drilz? chalk pencils and like them, but the line is not always as thin as I'd like. As far as the washable markers, my girls have t-shirts that have preprinted pictures on them (not colored in) and washable markers. They color the t-shirts and when they get washed the picture is blank again - all the marker comes out - and they can start over. I think I've washed 3-4 times now and the marker has always washed out. Try it on a pillow case or something - something you don't really care about. See if it works for you.