Thanks guys.
For those that are interested. The fabric I used is basically automotive headliner.
Foam-Backed Automotive Headliner Black | Fabric.com - Fabric.com
@bran3
If you have a rotocast helmet, I don't think you would need it. If you do use it, just keep in mind the extra space it would take. My ODST helmet has 1/2 inch to 1 inch padding, so I don't even touch the side of the helmet.