I'm I know that, I'm not sure what you're trying to point out though. That its a fake bar code or that I just have 'O-' on there already. I did that because I don't know my blood type, so I just picked on at random.
You didn't have to quote for my attention, I read all my comments
To the question, I vacuum formed my visor. Its cheap and incredibly easy, I just followed this video tutorial to make the former. For the mold, I cut out the visor from the helmet, sanded it very smooth, and build up the edges for attachment points. If you do it, make sure the mold is smooth, any marks and dents will show up in the visor. I tinted it with a transparent blue spray paint.