In my case its a FP premium, but when you pack a newly made helmet (fiberglass) in with styrofoam panuts, the peanuts can deteriorate the surface of the helmet.
The chemicals in the fiberglass resin will cause a reaction with the peanuts, and will leave shiny spots, marks, and even soft spots in the surface.
You NEVER want to pack fiberglass with the peanuts directly touching the surface.
In my case the helmet can be lightly sanded and then primered, but the finish on the FP helmet is so nice, it is a waste to dull up the detail with un-necessary layers.
Always be wary of what you put next to eachother when it comes to chemical based plastics.