I agree with man cave, use a sharp razor if it cleans off its probably old wax. Sometimes a challenge to remove. Elbow grease and keeping a sharp blade in the holder and perseverance. if your blade is sharp and in a holder you don't need heavy pressure just repetition. I just ran into this with a double sided six footer and it took a couple of days to get it off. Not one remover did squat. I tried everything I had.