Without the visor on, the front eye shield or whatever (the top peice that sticks out like a ball cap) that part sags the sides and leans over, thats why, I first tested my helmet on printing paper and it sagged, so i added the visor and it hold sup till today (but i remade it in cardstock for the final product)
If you dont want to add the visor, tape or glue a peice of cardboard or something from the top to the bottom for support, after resining, cut if off.