What type of printable material sticks to plastic hard helmets? The plastic is “Class e type 2” if that means anything. I was asked to do several helmet decals About 1.5” x 2.5” but my samples peel off too easy. I was also asked for reflective ones as well as plain ones. Also, what is a fair price to charge for each one? I find small stuff like that is difficult to price. Thanks!