What material shoud I print football helmet decals?

[CENTERVILLE SIGNS]

Or could I but wholesale ?

 

[J Hill Designs]

I would think something rugged like convex with thick lam

 

[Sign Works]

Convex - Gearwrap

http://www.convexvinyl.com/convex-gearwrap/

 

[BIG EASY DOES IT]

SUBSTANCE GRAPHICS has some very good vinyl just for this purpose with a thick laminate to match. Talk to them and they will get you set with the right material and a free sample roll of whatever you want to try.