My first endeavor in rock painting I used Sharpie oil based paint markers. I drew the picture on the bare rock. I wanted a glossy finish so I waited 20 hours. I then applied Krylon spray sealer and all the paint colors ran! :( Both of these products were recommended in a book I read on rock painting. Can someone tell me what I should have done differently or the product I should have used. In addition when the sealer dried, it wasn't glossy--would I need multiple layers of sealer?