I have an old exterior door with etched window that I have had in storage for several years. I brought it from an old house that was being torn down but before transporting I ran several strips of duct tape across the window. It has been left in storage that way for quit a while. Well I'm trying to cut down on the clutter and thought I would put the door up for sell but the adhesive on back of the tape is dried on the window. I don't want to use a scraper for fear of scratching up the etched window. What would be the best thing to use to remove it? I also have a recurve bow that has camoflage duct tape on it too. It has been on the bow for several years and is dry also.