You didn't specify how far you've progressed in "currently making a helmet". Are you starting a pepakura build? How do you intend to create the shape and structure? Obviously you have to start with some kind of framework. Many people are using Polyester resin or "Bondo" automotive body filler for the finish shape, but you usually start with an under structure. The resin can quickly become very heavy if too much is used to flesh out the dimensions. I personally chose to use very thin styrene strips about 1/2" wide. Glued the ends in a star burst pattern with the opposite free ends radiating out about a foot long in all directions. Then I made a ring for the bottom opening, bent all the free ends down to glue them to the ring. That gives you the basic bell shape you need. keep working up the sides of the helmet adding concentric rings as you go. I kept them about a 1/2" spaced untill I was happy with the look, then filled the gaps with more styrene. Last, I built the "Mohawk" with styrene and attached it to the top. Then I cut the front of the bottom ring out and shaped the brow area with more styrene. Then I fleshed it all out with the body filler. You can check the result in my thread "What a Lid/ Dredd helmet build". The pics are of a sanded but unfinished helmet. If you can handle pepakura, try that, although it will involve fiberglass resin to stiffen it. Good luck.
