I used my go to ,Ultra Clean washable Crayola markers, to mark my quilt. This time they didn't all wash out. I didn't realize it and dried the quilt. I have tried Zout and Spray and Wash and they are still there. Not as bold as before I washed it but there. This is the first time this happened and this is a quilt for a silent auction at my grandkids school. Any suggestions?